HAVERHILL — An accident reconstruction expert hired by the lawyer representing Haverhill teen Aaron Deveau, who is accused of motor vehicle homicide as well as texting while driving, admitted to having confused the names of the victim and the defendant in his analysis of what happened.

Retired Westborough Police Officer Ronald MacKendrick said he’d mistakenly listed Deveau as the driver of the car he hit, and who subsequently died.

“That would be an error,” MacKendrick said.

In yesterday’s third session of the trial, Deveau’s lawyer Joseph Lussier tried to prove that Deveau was distracted by a car in front of him when on the afternoon of Feb. 20, 2011 his car crossed the center line on River Street near Cliff Avenue and crashed head-on into another car driven by Donald Bowley Jr., 55, of Danville. Bowley, a father of three, died 18 days later from injuries which prosecutors said he suffered in the crash. Bowley’s passenger, his girlfriend Luz Roman, was seriously injured in the crash.

In testimony lasting more than three hours yesterday, Brian Roderick, a state police accident reconstruction expert, said he downloaded information from the “black box” in the 2001 Chevy Malibu that Deveau was driving. He said it showed that approximately three seconds before the crash Deveau was going 38 mph, at two seconds he applied his brakes, although Roderick said the data did not indicate how much pressure was applied to the brake pedal — then at one second before the crash he was going 25 mph.

Roderick said a 1992 Toyota Corolla driven by Bowley was traveling at about 20 mph when the cars collided almost head-on, at a slightly offset angle. Roderick said Bowley tried to avoid being hit, turned toward the side of the road and hit his brakes, causing a 21-foot-long tire skid mark in the road with his left front tire. When questioned by prosecutor Ashlee Logan, Roderick said that in his opinion Deveau’s car drifted over the yellow center lines and was in Bowley’s lane for between 2 and 2 1/2 seconds before the collision.

MacKendrick argued the car in front of Deveau’s affected Deveau’s view of the road ahead. He said that just over a half a second passed between the time Deveau crossed the center line and collided with Bowley, attempting to prove Deveau had not “drifted” across the yellow lines but had turned rapidly to avoid the car in front of him. MacKendrick also said Deveau’s car was going just 7 1/2 miles per hour when it struck Bowley’s car.

Logan questioned MacKendrick’s qualifications, saying he is not certified by “ACTAR,” or the Accreditation Commission for Traffic Accident Reconstruction and that he is not certified in downloading or analyzing information contained in so-called vehicle “black boxes.”

During testimony last week, Robin Murphy of Haverhill said she was driving in front of Deveau when she heard a crash then stopped her car. She told police she had no reason to put her brake lights on and that she was going straight ahead at the time. Logan questioned MacKendrick as to how Deveau’s “line of sight” would have been affected by the car in front of him, asking him what kind of car Murphy was driving.

“I do not know,” he said. “I do not know who Robin Murphy is.”

Moments after the jury was dismissed for lunch, Lussier entered a motion for a “directed verdict,” asking Judge Stephen Abany to dismiss the charge of driving while texting, saying there was no evidence to support it. Logan objected, telling the judge there is ample evidence that he was texting in the minutes leading up to the crash. Abany denied Lussier’s request. Final witnesses for the defense are expected to be called today.

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