WEST BATH (AP) – A Bath man has admitted to causing a fatal crash last summer in a construction zone on Interstate 295 in Topsham.

John Allen pleaded guilty Tuesday to being under the influence of prescription opiates, as well as manslaughter and other charges including drug trafficking. Under a plea agreement, he could serve eight years in prison.

Allen, 52, was driving with a suspended license last June when his car slammed into the rear of a sport utility vehicle, killing its driver, Harold Weisbein Jr., 44, of Topsham, a professor at Southern Maine Community College.

Assistant District Attorney Andrew Wright said a blood test showed that Allen was under the influence of methadone and oxycodone and a doctor was prepared to testify that the opiates “impaired his ability to drive.”

Allen has a record of accidents, license suspensions and driving violations dating back 20 years. After the crash, police seized 100 Oxycodone pills found in two unmarked prescription bottles in his home.

After the crash, Allen allegedly stumbled from his car and exclaimed to a bystander, “What the hell did (I) hit?”

Justice Thomas Delahanty told Allen that he could extend the prison sentence or reduce it based on the information he receives before sentencing, scheduled for June 6. Allen could withdraw his guilty plea if Delahanty recommends a longer sentence.

After the hearing, District Attorney Geoffrey Rushlau said he hopes the judge sticks to the plea agreement.

“If he were to give Allen anything less, it would diminish the seriousness of what he did,” Rushlau said.

Defense lawyer Richard Elliott said his client is remorseful. “There is not a day that goes by that John doesn’t think about what he did,” Elliott said.

“He wanted to take responsibility for his actions.”