FALMOUTH — Former Mattapoisett Police Chief Mary Lyons was found not guilty of operating under the influence Friday at Falmouth District Court by Judge Thomas Barrett, who said the evidence presented did not prove guilt beyond a reasonable doubt.

Lyons was found responsible for a marked lanes violation and ordered to pay $100.

Much of the testimony came in the form of video from the dash camera and body camera of State Trooper Patrick Bosworth, who arrested Lyons July 17, 2021 following a traffic stop on Route 28 North in Bourne. 

Lyons opted for a bench trial, which was decided by the presiding judge, rather than a jury.

For a good portion of the trial, which lasted about an hour, Barrett, alongside defense attorney Robert Nolan and Assistant District Attorney Maxwell Mitrokostas, watched and heard video from Bosworth’s cruiser and body cameras 

The state trooper also testified in person Friday that he observed the vehicle driven by Lyons, who was then the Mattapoisett police chief, drifting from the right lane halfway into the left lane before returning to the right lane. 

After he signaled for the car to stop, the vehicle drove into the breakdown lane and went into reverse for a few seconds before being placed in park, Bosworth said.

When he approached the vehicle, he said, he smelled the odor of alcohol, her eyes appeared glassy and her speech was slurred.

Lyons had difficulty exiting the vehicle, Bosworth reported, because she still had her seat belt on. 

In response to his request that she step out of the vehicle, she replied that she didn’t “feel I have to,’’ Bosworth reported.

After she did step out of the vehicle, Bosworth described her as unsteady on her feet, needing to hold onto the car to walk. 

He also questioned her fine motor skills, noting that it took her seven minutes to unclasp and remove a necklace at booking.

Defense attorney Nolan said that Lyons’ behavior could be explained. He said that the former chief, who is 62, has hip and knee problems that can make walking difficult.

Glassy eyes are natural, Nelson said, when police lights are flashing in a person’s face. “If your eyes aren’t glassy,’’ in that circumstance, “you’re probably dead.’’

The odor of alcohol does not prove intoxication, Nelson stated, noting that liquor can be detected on a person’s breath even if they have just one drink.

He also argued that Lyons initially was reluctant to exit the vehicle because, with her background in law enforcement, she knew that a reason had to be given for motorists to leave their vehicles.

When Bosworth then explained that he wanted to perform tests to make sure she was safe to drive, she immediately followed his instructions, Nolan said

Barrett agreed with the defense, saying that the Lyons’ gait in the video differed little from how she walked into the courtroom.

He said that her speech did not appear slurred in the video, and that some necklaces “are not easy’’ to maneuver. 

The evidence, he said in his decision, did not rise to the level of proving guilt beyond a reasonable doubt.

After the trial ended, Lyons said the verdict was “just.’’

She was placed on paid leave the Monday after the arrest and agreed to early retirement terms with the select board Aug. 5.

She said Friday she had always intended to retire at 62. She served the Mattapoisett Police Department for 36 years, including 21 years as chief.

She was replaced by Jason King, who served as interim chief before being named to the position officially in December.