CONCORD, N.H. (AP) — A man who has served more than half of his life in prison for his role in the 2001 stabbing deaths of two married Dartmouth College professors as part of a plan to rob and kill people before fleeing overseas was granted parole Thursday.

James Parker was 16 when he was part of a conspiracy with his best friend that resulted in the deaths of Half and Susanne Zantop in Hanover, New Hampshire. Now just shy of 40, he appeared before the state parole board, years after pleading guilty to being an accomplice to second-degree murder and serving nearly the minimum term of his 25-years-to-life sentence.

He could be released as early as May.

“I think it’s unimaginably horrible,” Parker said during the parole hearing when asked by a board member what he thought of what he did. “ I know there’s not an amount of time or things that I can do to change it, or alleviate any pain that I’ve caused.”