LITTLE ROCK, Ark. — Police in Little Rock say two suspects in the 2017 killings of a 24-year-old woman and her two young children now face murder charges in a fourth slaying.

The Arkansas Democrat-Gazette reports that police on Thursday announced capital murder and aggravated robbery charges against 25-year-old Michael Collins and his brother, 21-year-old William Alexander, in the death of 64-year-old Billie Thornton.

Thornton was found dead in his apartment in July of last year.

Collins and Alexander were already being held in the Pulaski County jail in the killings of Mariah Cunningham, 5-year-old Alayah Fisher and 3-year-old Elijah Fisher.

The three were found dead Dec. 5 in southwest Little Rock. Police have not said how they were killed, but have said that Collins knew Cunningham.