Lisa Steed was named Utah Highway Patrol's "Trooper of the Year" in 2007 for making more than 200 DUI arrests, but now all of her cases could be in question because she admitted she did not follow proper protocol while administering a DUI check.
It is the second time Steed's DUI arrests have gained notoriety. A 2009 dashcam video shows her Tasering a motorist who was later determined to be sober.
"The cumulative facts may well have a significant ripple effect across every case she's touched," Salt Lake City attorney Joseph Jardine told ABCNews.com. "This could become the basis for overturning multiple convictions in the past."
Jardine is representing Theron Alexander, who claims Steed violated procedure when she administered a breathalyzer test before a field sobriety test in March 2010.
"The credibility of an investigating officer is paramount. If you can't trust the cop at their word, there's very little left that you can trust with an investigation," Jardine said.
At a court hearing on Tuesday, Steed admitted that she had removed her microphone during the incident in order to perform an unauthorized action.
"She specifically stated [Tuesday] that she took the microphone off so her superior wouldn't know what she was doing," Jardine said. "We're concerned that she may have a tendency to stretch the truth when it suits her purposes. Our objective is to probe her credibility."
Steed's attorney Greg Skordas does not believe that the incident is any reflection of his client's credibility.
"It doesn't affect her credibility. It affects the way she does things, her ability to follow instructions," Skordas told ABCNews.com. "It doesn't mean she's dishonest."
Skordas said that Steed was simply trying to give the person she had pulled over "the benefit of the doubt" by skipping straight to the breathalyzer test and not having them get out of the car.
"It wasn't anyone she knew. I think she was just being overly sensitive," Skordas said. "There wasn't any bad intent. It was one of those, no good deed goes unpunished."
This is not Steed's first run-in with the law. In 2009, a police car dashcam recording caught her Tasering a man during a DUI stop after he refuses to get out of his car, saying he'd like to call a lawyer.
The man, Ryan Jones, can be heard calmly saying, "Ma'am, please don't shoot me with a Taser," before Steed zaps him and he beings to scream. When Jones was eventually tested, his blood alcohol level was a 0.03, well below the legal limit.
The case was settled in November 2011 when the state paid Jones $40,000 without admitting wrongdoing.
When asked about the Taser case, Skordas said, "She took her lumps, she was reprimanded and we move on."
"Unfortunately, you have 300 cases and two go south and then all of a sudden you have a history," he said. "She wasn't named Trooper of the Year because she has a history. She works very, very hard and had a couple of unfortunate incidents, which she also stepped up to the plate for."
Steed has not been charged with a crime at this point, but Jardine believes she has a "huge insubordination problem" that needs to be dealt with.
"It's hard to say why she would do it specifically," Jardine said. "Is it pressure from her past achievements? Is it her desire to outdo the other officers in the state? Is it for advancement? Is it for all of the above? Who knows?"