DUI expert witness, William Pelarenos, sat down with me to chat about DUIs. Any defense attorney who handles DUI cases needs to sit down with an expert. I learned so much in so little time with William. Listen to Podcast Episode 034 of the Criminal Nuggets Podcast to drop in our conversation.
Who is William Pelarenos?
William Pelarenos is a retired police officer from the Cook County Sheriff’s Department. He had over 30 years of law enforcement experience. His last assignment was part of a DUI unit that primarily focused on DUI arrests.
William was also an Illinois State certified standard field sobriety test instructor. He taught other police how to properly conduct field sobriety tests.
William has obtained thousands of breathalyzers samples. He was a state certified breathalyzer operator.
William has experience with
- Preliminary Breath Test Tests (PBTs)
- Recording Breath Tester (RBTs) (this one is portable)
- ECIR Breathalyzer
William’s Book, “DUIs Decoded” can be found on Amazon and Barnes and Noble.
From the Podcast
Click to tweet the following:
Click here – “I charge you nothing to come to your office and look at the case real briefly.
Click here – “I was teaching police officer classes, when I retired I opened it up to everybody.”
Click here – “Everything is based on errors and omissions.”
In one of Williams’s last consultations, he didn’t even have to testify as an expert. He was able to help prepare the defense attorney for cross examination of the arresting officer during a motion to suppress.
With William’s guidance, the attorney was able to demonstrate to the court that the results of the field sobriety tests in that case were so unreliable that in essence no probable cause existed for the arrest. Defense counsel one that motion. The case was dismissed. William never had the chance to take the stand as a DUI expert witness.
In other cases, much of the consultation can focus on the errors, omissions or problems with the case. For example –
- Improperly Administered Field Sobriety Tests
- Incorrect or Missing FST Directions
- Directions Out of Order
- Rushed HGN
- No FSTs At All
DUI Expert Witness
One of the most important ways a DUI expert witness can be helpful is to provide an opinion to counter the other opinion the judge or jury will hear in the case.
That’s the cop telling the court that in their opinion your client was wasted the night he was arrested.
Sometimes, a DUI expert can sift through case file and formulate an opposite opinion,
Additionally, a DUI expert witness may be able to educate a jury. Lets face it some DUI cases can get complicated and technical. Why wouldn’t you want an experienced expert in your corner helping you explain complicated issues to the jury (and sometimes a judge)?
Guess What? The Cops Making These Arrests Aren’t Experts
One big takeaway I developed after spending some time talking to William was that the very officers making all these DUI arrests, themselve, are not in any meaningful way experts in the DUI field.
“A DUI investigation is a scientific investigation.” – William Parenos
Part of a defense attorney's job is to stop and critically analyze whether the arresting officer performed these field sobriety tests in a careful, systematic, standardized manner. This very much the same type of behavior that a scientist looking for reliable results would follow.
William can help you get down to the bottom of it.
How to Reach William
William Pelarenos can be reached at
on Twitter at @policeproject1
by email at firstname.lastname@example.org
by phone at (708) 793-3980