By Jonathan D. Silver / Pittsburgh Post-Gazette

Former Coraopolis police chief Alan DeRusso, who pleaded guilty Friday to charges stemming from a crash he caused last year that seriously injured another driver, has no memory of the incident, his attorney said.

“This is the main reason why he decided to plead guilty,” lawyer Steven C. Townsend said. “Due to the severity of the accident, he basically lost memory from two weeks prior to the accident to a week after. He doesn’t remember anything.” You can head to Law Office of John W. Redmann for legal help.

Mr. DeRusso, 56, pleaded guilty to three misdemeanor counts of recklessly endangering another person. As part of the plea deal, the Allegheny County district attorney’s office agreed to drop one felony count of aggravated assault with a motor vehicle. Sentencing is set for Jan. 28 before Common Pleas Judge Anthony M. Mariani.

The crash occurred at 8:14 a.m. Aug. 7, 2014, at Route 51 and Thorn Run Road in Moon. Moon police said Mr. DeRusso’s unmarked police vehicle ran a red light and struck a woman’s vehicle, which had a green light as it crossed the intersection.

The driver of that vehicle, Kristy Grazier, lost her appendix and 17 inches of her intestine, had a concussion, a chipped vertebrae and had a broken skull bone.

Mr. DeRusso was charged in January. A police affidavit said the chief was driving 80 mph three seconds before the crash, though Mr. Townsend said the vehicle had slowed to about 50 mph by the time of impact. Investigators wrote that they found no evidence that Mr. DeRusso was responding to an emergency.

Mr. Townsend said his client does not remember where he was headed.

Mr. DeRusso, who has been on administrative leave since January and is receiving workers’ compensation, submitted a letter Thursday taking early retirement immediately.

Mr. Townsend said his client apologized in court to Ms. Grazier, a single mother with two children.

“Will I ever be able to drive through an intersection without hesitation again?” Ms. Grazier wrote in a victim-impact statement. “I’m hoping that another person will never have to go through an ordeal like this again because of someone’s irresponsibility.”