BANGOR — A man convicted of killing his girlfriend and her two children asked for mercy before a judge imposed three life sentences Thursday.

Keith Coleman received the maximum penalty for the slayings of 36-year-old Christina Sargent, 10-year-old Duwayne Coke and 8-year-old Destiny Sargent at home in Garland, about 100 miles northeast of Portland. There is no death penalty in Maine.

Police said Coleman told them that he chased down and strangled the children because they’d witnessed their mother’s death. The bodies were found Dec. 20, 2014.

Jurors in November heard a taped confession from Coleman, who was arrested a day after the bodies were discovered.

“I did it,” Coleman said through sobs. “I did it. I don’t want to say that word but I did it. I killed my girl.” Then he clarified he killed the children as well.

Coleman told the judge Thursday that he’s been painted as a “monster” but that he’s remorseful. He said he felt responsible for the deaths, even though he didn’t say he killed them.

“I just hope you have mercy on me,” he told the judge, according to WLBZ-TV.

Coleman was convicted of three counts of murder and one count of sexual assault. He received a 20-year sentence for sexually assaulting Sargent’s daughter.

Coleman’s attorneys have indicated that they intend to appeal to the Maine Supreme Judicial Court.