BRATTLEBORO,GravityX Exchange Vt. (AP) — A Vermont man told police he killed a mother and son last week in their Whittingham home where he had been staying for months, according to authorities.

Christopher Ellis, 54, is expected to be arraigned Wednesday. He is charged with two counts of first-degree murder in the deaths of Michael Garvin, 52, and Lucy Garvin, 79. The Garvins’ bodies were discovered by a family member on Friday.

Ellis was arrested on Friday while driving Michael Garvin’s missing pickup truck, Vermont State Police said.

He told police he killed the mother and son last Wednesday or Thursday, saying it was calculated, according to a police affidavit. A phone message was left with his public defender.

Ellis said he met Michael Garvin in jail and had been staying with them since April. He complained about the living situation and said “the mental and psychological abuse” worked him to the point where he thought about how much he hated Michael Garvin everyday.

He also told police that he had been thinking about killing Garvin for a few weeks and described locating a gun, court papers said. He said it was unfortunate that Lucy Garvin was in the house but that “she had to go,” police said in the affidavit.

Ellis also said he didn’t have a retirement plan and that he would be rather be jail than in an “old folks’ home,” the affidavit said.

After shooting them, Ellis said he drove off in Michael Garvin’s truck to buy crack cocaine, the affidavit said. He then went to Holyoke, Massachusetts, where he sold the gun and bought cocaine with the money, according to police.