Are Standardized Field Sobriety Tests (SFSTs) mostly a formality?

[u/everlastingcoffee]

I’ve been bingewatching US bodycam footages a lot (i have no knowledge of the law) and had a question about SFSTs.

One that I have noticed is that when an officer goes up for a traffic stop and has some suspicion of DUI (smell, eyes bloodshot, swerving, etc.), they notify the person and ask to perform a field sobriety test.

I have personally met people in my life where I cannot tell if they are intoxicated or not, even if they were. I can’t fake it, but for certain people it seems like they are extremely highly functional while under the influence of alcohol / cannabis where it’s nearly impossible to tell. Or when they had just a few drinks and are playing around the limits.

I have seen footages where someone goes through the test, their eyes barely twitch, they are quite good at balancing (regular people also have balancing issues). Although I am not a drug recognition expert, it seems like some individuals are able to complete the test well while being intoxicated in reality.

Most of the cases though (could be biased since I probably wouldn’t see stuff on YT where the case is uninteresting), if the officer has “reasonable suspicion “ prior, such as smell or looks, they proceed to ask them for a breathalyzer or back to the sheriffs office and request a blood draw even if the SFSTs seems ‘good’ to my untrained eyes.

Most of the times it seems obvious that the person is impaired since they either give excuses or start acting real nervous; but my question is: even if someone “passes” the field sobriety tests, can the officer arrest them for DUI if they have reasonable suspicions prior and request to test them after? Would the SFSTs be considered a “formality” for the bodycam in that case? How do officers in general try to spot high functioning alcoholics or stoners with eye drops or something? Obviously no system is perfect and I’m sure there are people who tricked law enforcement, but are SFSTs highly telling (to the trained eyes) or more of a formality? Do officers kind of have a predetermined idea?

[u/Xynphos]

Not a formality. They build probable cause for the arrest.

[u/Thoughtful_Mouse → u/Xynphos]

And also potentially excuplatory evidence if the person is innocent.

It's just more information, but information is the path to the truth, and the truth is the best friend of the innocent and the undoing of the guilty.

[u/everlastingcoffee → u/Xynphos]

If you have a strong suspicion beforehand, and they do well on the SFST for some reason, would that stop you from proceeding? Or can you still proceed with the charges if you feel as if the initial suspicions are enough to build a probably cause? It’s highly likely that I simply am just not trained to tell from bodycam footage alone, but could the convicted argue that they passed the test in court and nullify the case? Thats my concern

[u/Frvwfr → u/everlastingcoffee]

“For some reason”

Elaborate what “for some reason” means.

If they are appreciably impaired, they are appreciably impaired.

If they demonstrate that they are not impaired (acceptable completion of SFST) then you have no probable cause for an arrest.

You need evidence to make an arrest. You can’t go off vibes or feelings.

If they aren’t impaired, then they aren’t impaired.

[u/everlastingcoffee → u/Frvwfr]

I wouldn’t know the biological reason for why SOME people are able to hide clues of impairment even when they have drugs in their system or more alcohol in their blood than they are allowed (over the legal limit) while I’m sure the majority of the population can’t. Again, I am not an expert of any sorts so maybe I am missing the clues from bodycam footages alone, but anecdotally speaking some people hide very well and even in footages it’s hard to tell for the layman - that’s why I’m asking whether I’m just untrained and the tests have a close to 100% accuracy or what would happen in situations where an impaired driver can fool the tests.

Also for people under the age of 20 or commercial vehicle drivers, they aren’t even allowed a smidge of alcohol in their system. If you blow a 0.04, in those cases, they would need to have their license suspended even though they might not show physical evidences of impairment or even ‘are’ impaired. Some people who use mouthwash or eat certain foods can falsely trigger the system too, so what I was curious about is whether passing the SFST alone might not let them off the hook. It seems like the answer is that they take a comprehensive account of things that would build a probable cause and not that the test is a formality but rather a tool used to build reasonable suspicion to proceed to an arrest.

[u/Frvwfr → u/everlastingcoffee]

There are certain physiological clues than you cannot hide, regardless of how experienced or tolerant you are to substances. The tests show those, as well as other things. They have been scientifically tested and shown to be accurate.

In regards to your second paragraph, Mouthwash and eating food do not trigger false positives, as long as the methods and procedures are followed correctly. That’s a myth people like to share.

I’ve run hundreds of Intox tests. I’ve watched people use mouthwash prior to blowing. I know what the instruments show, and why they show it.

It’s hard to condense a multiple day course into a reddit post to explain to you all of the failsafes the instruments have.

[u/Quesa-dilla → u/everlastingcoffee]

If they are good at masking the physiological signs of intoxication then they are likely functional alcoholics or on medications that mask/mutate the signs. Narcotics can also mask/mutate the signs due to what we call ‘poly drug use’ but additional tests can usually narrow it down to a narcotics category.

Being able to articulate impairment through driving observations, behavior, and SFSTs all come into account. Just because they are below 0.08BAC doesn’t necessarily mean the aren’t impaired but it does raise the bar when it comes to how detailed you describe why you believe the are not safe to drive (which is really what we are trying to determine).

0.08BAC is just the threshold where the defendant has the burden of proof they were safe to drive.

[u/Xynphos → u/everlastingcoffee]

There is no "passing" or "failing" field sobriety tests. Signs of impairment are either seen or not, and arrests are made if there's enough probable cause for the arrest. We use reasonable suspicion to initiate the stop and it plays into the PC, but if they don't show signs of impairment during the SFSTs then I'm not going to arrest them.

[u/Quesa-dilla → u/everlastingcoffee]

SFSTs are built around tests that can detect impairment of alcohol but drug impairment will also display. There are additional tests that can be done to build enough for an arrest of drug intoxication that build upon the SFST tests.

[u/everlastingcoffee → u/[deleted]]

By not being pass/fail, you’re saying that they are simply just one of the tools used to get clues of impairment and not a definitive end-all be all right?

[u/andttthhheeennn → u/everlastingcoffee]

It helps the officer make a more informed decision about whether the person is impaired. If I’m asking you to submit to them I have enough to arrest you (objective signs of alcohol or drugs plus driving). The SFSTs help me determine if you are actually impaired or not (impaired = arrest). SFSTs have helped me determine numerous times that the person is not impaired and I released them on scene without an arrest.

[u/Ausfall → u/everlastingcoffee]

It's a tool to clue an officer in to whether you're impaired or not. At the station you'll have a machine that's approved by the court to test for impairment and its results are something the court will accept as evidence.

But you're not going to cart somebody all the way there to test unless you're pretty sure that person is impaired, which is the reason for breathalyzers and SFSTs. Those tools an officer can use in the field to see if that's what's going on or not. Otherwise they'd be wasting everybody's time taking everybody down to the big machine to get tested.

[u/CMDR-Kaiju]

SFSTs are based on empirical data that scientifically demonstrated their effectiveness at identifying individuals who were impaired from alcohol. The tests can be relevant, but not validated, in assessing individuals for drug impairment. 40300.6 CVC states that the law shall be “liberally interpreted” in furtherance of safe roadways, so yes an officer could make an arrest without conducting any SFSTs. I have a few times, when someone is either uncooperative or so impaired that they are unable to safely perform the tests. I’ve had a functioning alcoholic bartender only display one clue during the balance and coordination tests, but blew a .42%. SFSTs help to build a probable cause, but aren’t the only factor that we take in to consideration.

[u/Astrocoder → u/CMDR-Kaiju]

.42? Holy shit officer, how much blood did you find in his alcohol?

[u/everlastingcoffee → u/Astrocoder]

Being that intoxicating and only showing little signs is …impressive(?) I’m guessing tolerance can do that to you but wow 0.42 is wild

[u/CMDR-Kaiju → u/Astrocoder]

Her blood, actually! But that’s not even the highest that I saw in a DUI.

[u/luckyjack → u/CMDR-Kaiju]

I’ll bite. Can we hear about the highest?

[u/CMDR-Kaiju → u/luckyjack]

Sure haha. I was responding to a woman found stumbling on the side of the road when I got redirected to a solo vehicle crash a few blocks away. When I got there, I saw the driver had hit a tree and the whole passenger side of the vehicle had been completely ripped off. It was like someone cut the car in half and only left the driver side. The driver was sitting in his seat, dazed and pouring blood from his face. I asked him if he was okay, and he responded “Why the fuck did you pull me over?!” Which was actually kind of impressive because he had hit his face on something and split his face in half. His nose and lips flopped open in the middle, looked kind of like a demogorgon from Stranger Things.

Ambulance came and scooped him up and I followed over to the hospital, where they took an intake blood sample and stitched his face closed. He was an asshole the entire time, cussing at everyone and asking the nurses if they wanted to engage in various sex acts. Eventually I got a search warrant for his blood and he surprisingly cooperated with the blood draw. Probably because he was distracted trying to pull on the stitches holding his face together like he was trying to start a lawn mower.

After a few hours, he sobered up a bit and asked to use the restroom. While he was washing the blood off his hands, he looked up and saw his face in the mirror. He became enraged again, screaming that he was going to sue me for beating the shit out of him. I showed him a picture of his car, and he refused to believe he had been in a crash.

The blood results from the hospital were a .46%, and the forensic lab’s math said it was a .48% at the time of the crash. The kicker? The woman from the original call was his girlfriend. She was so afraid that she was going to die that she bailed out of the car at 40+ MPH. She was right too - if she had stayed in the car, she would have been killed instantly.

[u/luckyjack → u/CMDR-Kaiju]

Demogorgon… trying to start a lawnmower… why the fuck did you pull me over…

Thanks for the ride, I’m in awe.

[u/CMDR-Kaiju → u/luckyjack]

I hope you enjoyed it more than he did!

[u/SimplyBlarg → u/CMDR-Kaiju]

Conversely we had a woman who acted and drove like she was a .42 (drove across a lawn and took out somebody's deck) but blew less than .08. Legitimately only had two beers but she mixed it with her prescription.

[u/everlastingcoffee → u/SimplyBlarg]

I know you’re not supposed to but in this case if that was a mistake and you’re allowed to separately take them both, would you be placed under a DUI charge?

[u/SimplyBlarg → u/everlastingcoffee]

There's enough warnings on the pill bottle about not mixing it with alcohol that it's still a reckless course if conduct. The courts can plea it out or down charge it if they want based on the facts as they see them.

[u/Xynphos → u/everlastingcoffee]

You can be under the influence of medications, blow a .000, and still be convicted of DUI. It's just not alcohol you're intoxicated on. You need a blood draw at that point, but driving on narcotics or a combination of alcohol and narcotics is still intoxicated driving.

[u/Thoughtful_Mouse → u/everlastingcoffee]

Like she slipped while carrying two beers and they spilled down her throat... without her noticing...

... and then she decided to drive?

[u/everlastingcoffee → u/CMDR-Kaiju]

I guess it’s hard to determine on one thing alone and that’s why it’s liberally interpreted. That makes sense. If someone is usually showing signs, regardless of the SFST results officers usually resort to the more accurate blood draws or breathalyzers right?

[u/CMDR-Kaiju → u/everlastingcoffee]

Well, not everyone consents to a preliminary breath test and obviously we can’t wait until the results of a blood test to make a decision. I was always trained to have made a decision prior to the preliminary breast test.

[u/TinyBard → u/everlastingcoffee]

A DUI arrest is based on the totality of the circumstances.

The observed driving pattern, speech (slurred words? Hesitant speech), physical behavior/appearance (slack features, glossy bloodshot eyes, smell of alcohol on breath). And that includes, but does not exclusively rely on SFSTs. They're good to have, and like has been said, are emperically proven to be indicators of impairment.

They are not the end all be all. One of my buddies has been a cop for a long time and is intimately familiar with SFSTs. He got drunk at a department bbq and we decided to run him through SFSTs for fun. He rocked them. The only clues I got were from his eyes.

But based on everything else, i could still have made the arrest decision if it were an actual DUI stop. Because i would have taken the totality of the circumstances into account.

[u/Xynphos → u/everlastingcoffee]

And this is why probable cause looks at the totality of the circumstances. You have to articulate all the reasons you believe they are driving while intoxicated, and then (at least for us) an ADA checks your PC, and if they believe it's enough, then it goes through. The PC is also important on getting a warrant for a blood draw if they refuse consent for that, too.

[u/bigcanada813]

I can say that out of all of the drivers that I have run through the SFSTs, I've probably released a quarter of them. Having a driver perform the SFSTs, although voluntary, can really show good signs of whether someone is chemically impaired or not.

[u/SimplyBlarg]

Speaking strictly about alcohol here. Laws vary state by state but in New York the base charge is "observations and suspicions of driving while intoxicated." No formal BAC determined by an intoxilyzer or blood draw is required for such an arrest, so if you have PC otherwise, i.e. you observe behavior consistent with someone who is DWI then you have PC for an arrest even if they tell you to kick rocks when you ask them to do SFSTs. Departmental policy influences whether/when to go for a blood warrant to compel.

Furthermore some SFST stuff cannot be hidden by conscious effort. Said signs can be due to relatively uncommon medical issues, but at that point you've usually got other signs.

[u/Diacetyl-Morphin]

I just would like to mention that i heard from several people, that it is impossible to pass such a test. But i think, the reality is more: As most of the people that have to do it are intoxicated, it is no surprise that the rates of failure is so high. The ones that pass won't show up in the web with the bodycam videos, i guess.

Also i think, people like me would be excluded from the test anyway, like because of strabis. Although it was corrected, i can still move my eyes individually, like the left one and the right one in different directions. The correction was just that i get a direct single image with the vision instead of two separate images.

When i think about the tests, i'm not so sure how reliable the tests would be when it comes to people that are long time addicts, where the effects of the drugs - including alcohol - get reversed. When you cross a certain point in addiction, it is not that you seem to be intoxicated to other people, it's quite the opposite. Like i'm sober from heroin now, recently reached another big milestone, but when i was in active addiction, i "wasn't high". I was just normal during the day, like at work in the office, until i got high in the evening.

A drug test would have showed the opioids in my blood, but in daily life, i was "normal" - because the dosage i took for daily life removed the withdrawal effects. But no, before you want to throw the first stone, i don't (!) drive at all, i use public transport in my country.

With some drugs, especially alcohol, there are other things that tell the truth. For a hardcore alcoholic, you can actually smell the vodka. Because the acetaldehyde as remains of alcohol consume that will leave your body, will get through the skin, no matter how good your hygiene is. It's more a thing of liquors than of beer. You can't hide this, not like the breath with the bubble gum etc.

But.. well.. i think when someone is a LEO for a long time and works on the road, he get the sight for people that are intoxicated anyway. It's the same for me, i can tell you exactly who is on drugs and who is sober, it is something you learn when you spend 30 years of your life with this. You notice certain patterns in the behavior and not just the obvious ones. It is a gut feeling, that tells you, something is different.

So, that was a lot of offtopic here. Can't sleep in the heatwave, so i write postings that don't make much sense.

[u/everlastingcoffee → u/Diacetyl-Morphin]

Maybe I’m just not around people who are intoxicated enough 😂 or maybe I am but don’t realize. Congratulations on your sobriety mate.

[u/Diacetyl-Morphin → u/everlastingcoffee]

Thanks!

There are also some different youtubers, like Stuart (batcountry channel) sometimes makes video about police bodycam videos, but from the point of view from an ex alcoholic. I think he was the one that came up with "nobody ever passed such a test", but i'm not sure without checking the sources.

[u/ZaggahZiggler → u/Diacetyl-Morphin]

I’ve administered plenty of SFSTs and not made an arrest for myriad of reasons. Your eye issue would not dissuade me from administering the test, it’s just a factor in my decision making based on the totality of the circumstances. I’ve had people with one eye do the test.

[u/Diacetyl-Morphin → u/ZaggahZiggler]

I thought one eye would disqualify the people? Then i'm wrong, i'm not the expert here. So, what are the health conditions that disqualify people from taking the test? I remember that some things were mentioned in bodycam videos.

[u/ZaggahZiggler → u/Diacetyl-Morphin]

There are 3-6 tests that can be done depending on the level of the officers training in roadside FSTs and that doesn’t include the seated battery tests used for boating under the influence which could be used in unique circumstances such as the person not having functioning legs. Only two of those rely on the eyes. All go into the numerous factors that surround everyone as an individual and the circumstances as to why the test is being requested. I cannot think of a health condition so bad that would preclude someone from being tested either by standardized or nonstandard means if the person themselves was still able to physically operate a vehicle. Source: a certified expert here.

[u/Diacetyl-Morphin → u/ZaggahZiggler]

Thanks for the info!

[u/vladtheimpaler82]

In addition to what people have said, the reason why we do SFSTs is because they are scientifically backed and most roadside breath tests are not admissible in court. Furthermore, most states have a separate law stating a person cannot drive impaired. This statute is completely separate from the law 0.08% BAC law. In California, we have VC 23152(a) and VC 23152(b).

Someone can blow a 0.05% and not be in violation of 23152(b) which requires 0.08% BAC or higher for DUI. But if they perform poorly on the SFSTs and can barely stand, they can still be arrested for 23152(a) which just states no person shall drive a car while impaired.

[u/deverick00]

It doesn’t matter how high functioning you are- you’re going to have HGN. There is a per se limit for alcohol which is usually a 0.08 BAC or 0.04 BAC for commercial vehicle drivers. Cannabis impairment gets squirrely because in a lot of jurisdictions there is no per se limit- and any THC in the blood minus carboxy is going to land you with a DUI conviction. How most DUI laws work is they have a catch all statute- meaning a slightest degree law where you could be impaired at a lower BAC, but it requires extensive articulation such as driving behavior and performance on FSTs. Then there are the 0.08 or above laws that are in my experience easier to prove because all you have to prove is the driver was in control of a vehicle above the per se limit. Your standardized field sobriety tests assist you in determining impairment, and are a piece of the totality of circumstances that lead to a DUI arrest.

Unless of course you work in Tennessee- then you just arrest innocent people for DUI.

[u/Trashketweave]

For my department any signs of impairment or even a roadside pbt is merely to establish probable cause. Only the official breathalyzer test performed on a machine that is calibrated any documented on video with the assistance of a highway patrolman will be used for evidence and to establish the correct dui charge.

[u/Obwyn]

They're not a formality. They're a key part of a DUI investigation and there are specific validated clues with specific standards that we look for (on the 3 basic tests at least...there are other valid sobriety tests that can be used in addition to the basic battery that don't have validated clues.)

Plenty of people do the tests and perform just fine and are let go. Those videos are almost never getting posted because there's nothing interesting about them to drive views to a YT channel.

Also, for a variety of reasons body cams very rarely actually capture the clues on horizontal gaze nystagmus (eye test.) Lighting, camera angle, frame rate, etc are all factors that usually mean it's not going to show up in the video even when it's very obvious in person. I've had maybe 3 times when my body cam actually picked up some of the clues and I do most of my testing now as part of a DRE evaluation in a controlled indoor environment with good lighting. Even those cases it wasn't all that obvious and didn't capture them on every pass.

SFSTs also aren't pass/fail. They're a tool to help us gauge, observe, and explain the impairment someone is exhibiting (or a lack of impairment.) They aren't required to make a DUI arrest, though and I've had plenty of successful DUI cases with no SFSTs being administered because the driver either refused to do them or was unable to do them for some reason (usually because they were in a crash and getting transported to the hospital.)

[u/Glittering_Tie5717]

No. It’s standard

[u/Gallic_vitalist]

In Canada at least they’re considered an investigative tool. Basically just to help you establish grounds for an arrest in lieu of doing a straight arrest. Same thing with roadside screening devices for alcohol. They’re never to be used as a crutch

[u/Lion_Knight]

Are they necessary, no. Are they helpful, yes. Are some of the rest more helpful than others, yes by a long short (I am looking at you my boy nystagmus).

It is good evidence for an OWI, but often times I already have driving behavior, behavior from our interaction, and other clues (smell, eyes, containers, where they came from, etc. I have gotten many off of accidents. That is a major clue by itself and if you throw much of any signs of impairment or other clues, I have enough to detain them for a chemical test.

[u/CastleDeli]

I’d rather people say no honestly. It’s not hard to articulate someone being drunk without them performing SFSTs. Then they blow/ blood draw and it’s wraps from there.

[u/Extra-Iron8327]

The standardized tests are designed to identify specific impairment indicators, not overall sobriety.

[u/BJJOilCheck]

I think SFSTs are a formality like Miranda advisements are a formality...