Darren Vann, 44, of Gary, Ind., was charged Monday with five more murders, bringing the total to seven.
The alleged female victims are identified as: Teaira Batey, Kristine Williams, Sonya Billingsley, Tanya Gatlin and Tracy Martin. All are death penalty cases, according to court records filed on Monday.
The new charges come about a year after authorities said Vann confessed to the murders of seven women, all similar circumstances. However, he was initially charged in only the killings of Afrika Hardy and Anith Jones.
Vann met the women through an escort service, most were killed and left dead in vacant buildings.
He was arrested in October 2014 after one of his victims was found strangled inside a motel room.
He had met Hardy, who was 19, through a so-called escort agency on the internet.
Vann went by the nickname "Big Boy Appetite" and police said he admits having strangled Hardy while wearing white gloves and using an electrical cord. He then put her body in the bathtub, turning on the shower and leaving the room.
Her killing and his arrest brought an end to a serial streak of murders in and near Gary, Ind.
Lake County prosecutors said Vann killed sometimes when the sex became too rough, and call that a "rage killing."
In some cases authorities allege Vann killed for money.