A suspect initially charged with capital murder in the December 2017 slaying of an 89-year-old Mobile man pleaded guilty Tuesday to the lesser charge of intentional murder as part of an agreement with prosecutors, according to court records and a published report.

Gregory O’Neal Hackett, 34, of Mobile, pleaded guilty on Tuesday in connection with the killing of 89-year-old Mobile resident John Higby, who was fatally shot in broad daylight in the parking lot of a Dauphin Street shopping center on Dec. 27, 2017, records showed.

Court records did not indicate what charge Hackett pleaded guilty to, but Fox 10 reported it as intentional murder.

Under the agreement, Hackett will serve a life sentence in state prison but has a chance at parole after serving 15 years, the station reported.

Hackett’s sentence was also not in court records as of Tuesday night.

At the time of his arraignment, Hackett pleaded not guilty by reason of insanity.

His attorney told Fox 10 he suffered from mental illness that began to manifest when he was 19 years old in Boston.

“Now he’s riding around the streets of Boston naked on a bicycle,” the attorney, Jeff Deen, told Fox 10. “We think he had schizophrenia way back then, banging his head into walls, trying to get the devil out. And I mean, this Mr. (Higby), the deceased, fine gentleman, comes from a great family; no sense to it. But overall, this was the best disposition, I think, going both ways.”