Darren Vann, convicted sex offender suspected of murdering at least seven women and leaving the bodies in abandoned houses in northwest Indiana, was deemed a "low" risk by the Texas Department of Public Safety sex offender registry, according to The Associated Press.

Forty-three-year-old Vann was also married to a woman 29 years his senior, The Daily Mail Online reported.

The Daily Mail found Vann's older ex-wife, 72-year-old Maria Vann, a mother of three who has decided to keep herself away from Vann since divorcing him in 2009 citing irretrievable breakdown, according to The Daily Mail.

"I'm tired of talking about this. Darren Vann was my ex-husband. I'm fed up with this," Maria said, the Daily Mail reported. "It's been six years, he was in jail. I don't want to talk about it."

Vann may be a serial killer who has killed others in the state as far back as 20 years ago, local police said on Monday, the AP reported.

Vann, of Gary, Indiana, was charged in Lake County with one of the seven murders, and was being held in custody, said John Doughty, police chief of the neighboring city of Hammond, according to the AP.

Vann is a registered sex offender from a 2008 assault in Texas after he was charged with sexually assaulting a 25-year-old woman and served one year of his five year sentence, the AP reported.

Vann was arrested in Gary on Saturday, a day after police were led to the slain body of 19-year-old Afrika Hardy in a Motel 6 in Hammond, according to the Daily Mail.

Doughty said Hardy had advertised sexual services on the classified ads website Backpage.com, and that she and Vann met at the motel, the AP reported.

After Hardy did not return from the appointment, a woman who had helped to arrange the encounter went to track her down and found her dead from strangulation, according to the AP. Vann admitted to all the murders and led police to the bodies of the six other women after being taken into custody.

"It could go back as far as 20 years based on some statements we have and that's yet to be corroborated," Doughty said, the AP reported. "It is possible other victims could surface."

Doughty also said it was not known if the victims were murdered in the abandoned houses or if their bodies were dumped there, according to the AP.

Doughty said the victims included Anith Jones, 35, of Merrillville, Teiarra Batey, 28, of Gary, and Christine Williams, 36, also of Gary, but three other victims have not been identified, the AP reported.