A New York State Police forensics expert testified on Wednesday that Kevin Monahan’s gun is not defective, but admitted that she had to perform one of the tests again because she could not be sure that the safety was engaged.  

Victoria O’Connor of the Forensics Investigation Unit was on the stand for over an hour in the murder trial of Monahan. The Hebron man is accused of shooting and killing Kaylin Gillis, a passenger in a vehicle who had mistakenly pulled into his driveway.  

Monahan used a 20-gauge shotgun, investigators said. His attorneys have argued that he did not mean to fire the second fatal shot, but slipped on his deck and the gun discharged.  

O’Connor confirmed that the bullet that was recovered in the Ford Explorer had markings that were consistent with Monahan’s gun. 

O’Connor explained the process that she uses to perform what are called “drop tests” of long guns in which they are dropped through gravity.   

She performed six drops at four feet with the safety engaged and six drops at one foot in height with the safety disengaged.  

In one of the four-foot tests, the gun had fired, and the safety was disengaged.  

“I could not confirm after the fact whether the safety was engaged prior to dropping it,” she said.  

She repeated that test with a second person verifying that the safety was engaged before each drop. The gun did not discharge in this instance. 

O’Connor said she did not notice anything out of the ordinary with how the shotgun was operating.  

She noted that each time after the four-foot drops, the safety button on Monahan’s gun shifted slightly but it did not disengage the safety and fire the weapon.  

“Based on your training and experience, is this gun as submitted in good working worder?” asked District Attorney Tony Jordan. 

“Yes, it is,” O’Connor said.  

On cross-examination, defense attorney Arthur Frost was persistent in his line of questioning whether the internal mechanisms of a long gun couldn’t release and cause the hammer to strike the primer and cause a discharge.  

Frost also criticized the testing error. 

“Whose job was it to make sure the safety was engaged for that second drop?” he said.  

When O’Connor said it was hers, Frost responded, “You don’t know whether you did your job?” 

Testimony wrapped up at about 4:30 p.m. and will continue Thursday morning.