CROWN POINT, Ind. (AP) — An Indiana man who confessed to killing seven women told detectives that his anger at being imprisoned years earlier drove him to kill.

Prosecutors filed five murder charges Monday against 44-year-old Darren Vann of Gary in the deaths of women whose bodies were found across northwest Indiana. He had already been charged in two other killings, including that of 19-year-old Afrikka Hardy. Vann was arrested Oct. 18, 2014, a day after officers found Hardy strangled to death inside a Hammond motel room.

The (Munster) Times cites an affidavit in which Vann says he killed the women because he felt he never should have gone to prison “the first time.”

Vann served time in prison for assaulting an Indiana woman in 2004 and raping a woman in Texas in 2009.