Pennsylvania Officers take note

Discussion in 'Cop Talk' started by ctaggart, Apr 5, 2010.

  1. ctaggart

    ctaggart

    Messages:
    1,507
    Likes Received:
    1
    Joined:
    Dec 4, 2007
    Here's a little bit of info regarding the use of PBT's in DUI arrests and whether or not to list the results on the DUI criminal complaint.

    As an aside, these damn PBT's are so accurate when calibrated it really irks me that you can't testify to the results other than being positive or negative. In DUI's it really doesn't matter to me, but with public intox or underage drinking I think it's a great tool that the Commonwealth just won't recognize as being such.

    Here's the email.
     
  2. FiremanMike

    FiremanMike Way too busy

    Messages:
    4,232
    Likes Received:
    787
    Joined:
    Jul 26, 2007
    Location:
    The interwebs
    Really? I have seen with my own eyes a PBT reading of .172 with a datamaster result (20 minutes later) of .080..
     

  3. OLY-M4gery

    OLY-M4gery

    Messages:
    2,585
    Likes Received:
    527
    Joined:
    Nov 7, 2001
    Location:
    Southern WI
    So? It was 100% accurate in detecting the presence of alcohol in your example, and should be evidence of underage drinking.

    Next, breath tests, whether a PBT, an automated PBT, or an evidentiary breath test instrument, rely on the test subject to provide an adequate breath sample. Some are better at others than disallowing weak samples.

    I arrested a DUI, and used blood as my test, about 1 hr later the arrestee demanded a breath test. That was given. The test result was .12 BrAC.

    The blood from 1.5 hours earlier was .17 BAC.

    No one is saying a PBT is the same as a test instrument, but they are used to confirm an officers observations and PC. Not to give a reported value at a Trial.
     
  4. ucop27

    ucop27

    Messages:
    76
    Likes Received:
    1
    Joined:
    Apr 4, 2009
    Location:
    Rochester, NY
    I agree 100% with your last statement.

    We all know blood is going to show a more "true" reading of BAC over a Datamaster everytime (remember breath tests under report a person actually bac).
     
  5. Steve in PA

    Steve in PA

    Messages:
    2,347
    Likes Received:
    59
    Joined:
    Mar 1, 2000
    Location:
    Pennsylvania
    We have never used the results from a PBT on a criminal complaint. A PBT is only used to confirm or deny the presence of alcohol.
     
  6. Steve in PA

    Steve in PA

    Messages:
    2,347
    Likes Received:
    59
    Joined:
    Mar 1, 2000
    Location:
    Pennsylvania
    The PBT we use (RBT-IV) can be calibrated and when used with the wet bath system, used just like one of the bigger machines. We don't use it as such, since going for blood is much easier.
     
  7. DaBigBR

    DaBigBR No Infidels!

    Messages:
    8,798
    Likes Received:
    14
    Joined:
    Oct 28, 2005
    Location:
    Circling the wagons.
    I handle PBT calibration for my agency. Properly calibrated PBT devices used in a proper manner to obtain a valid sample are very accurate. Large discrepancies in results between PBT and in evidentiary test (breath, blood, urine) can be influenced by a huge number of factors. The simple fact that you have had discrepnacies between results does not in and of itself indicate that anything is wrong with the PBT device (or evidentiary test for that matter) in and of itself.

    A few things to remember:

    -There is ALWAYS going to be some margin of error, generally expressed in a percent. This means that you will be farther "off" at higher BAC. Our state recognizes a 5% +/- "accepted margin of error" on the Datamaster evidentiary breath testing instruments. My conversations with the technicians indicate that the true marin is more like 1%-3%. Assuming the same margin of error for a PBT and then considering that one instrument could be up and the other could be down, then you may be looking at up a 10% difference, easily.

    -Breath sample composition can effect results. Officers who are negligent in the administration of the test will up their chances of seeing inaccuarte results. I frequently see officers administered PBTs without inquiring as to when the last drink was or checking the subject's mouth.

    -The manner in which the sample is provided may effect the results. Evidentiary breath testing instruments generallly require the person to expel a certain amount of air AND have a "leveling off" of the BrAC. On the Datamaster series of instruments, this is handled by a "slope indicator." In other words, even if the person has provided the requisite amount of breath, the instrument will not accept the sample until the result stops increasing. Deep lung breath should always result in a higher (but more accurate) result.

    -The subject providing the sample can also effect the results intentionally (or intentionally). One thing that I have noticed with the newer devices that sample automatically (Intoxilyzer SD-5 and Intoximeters FST) is that if the subject inhales (because they are out of breath) as the instrument capturesthe sample, the result can be affected. I recently backed an officer who had terrible field sobriety results, but a .06 PBT. The subject's true result was closer to .16 when tested again and without an inhale through the tube at the end of the breath.

    My state, like the one in the OP allows PBT for determining probable cause for arrest, but not in a criminal trial. We have ALWAYS put PBT results in the complaint as it is still a piece of evidece used to make a determination to arrest. In some cases, drivers will refuse field sobriety, but take a PBT (I know, weird), and in those cases, it may be a bigger chunk of the available evidence.

    We also DO allow the use of a PBT for Public Intoxication and Underage Consumption trials.
     
  8. OLY-M4gery

    OLY-M4gery

    Messages:
    2,585
    Likes Received:
    527
    Joined:
    Nov 7, 2001
    Location:
    Southern WI
    I don't know that I can say always or never about PBT results. But I know it has become an important factoid when I was charging someone with felony bail jumping for violating the no drink clause.

    We use them for underage alcohol consumption invstigations, and the results go on the citation, and in the report. I haven't been to any Trials for that.

    We don't have public intoxication laws, so I'm no help there.

    The original pasted e-mail, which references not wanting to unduly influence Judges................ I guess it makes sense if you think your Judges are as smart as dish water. My expectation is that Judges should be able to weigh the type and quality of evidence presented, in determinig whether a crime was committed, and if there is probable cause the defendant committed that crime.
     
    Last edited: Apr 6, 2010