MCKINNEY (CBSDFW.COM) – More potential victims have come forward in the investigation of a McKinney man accused of raping women using the online classified site Craigslist.

Police will not provide an exact number but say that a number of credible accusers have contacted them since Roger Stulce’s arrest was reported last week.

One of those accusers is Stulce’s ex-wife who called him a “monster” when we spoke to her late this afternoon. The 40-year-old remains jailed in Collin County for two sexual assaults.

They allegedly took place inside an apartment at the Villas of Eldorado in McKinney.

McKinney Police say Stulce lured unsuspecting women there by posting ads on Craigslist offering free or reduced rent if they would keep the place clean while he traveled for work. Stulce was arrested for soliciting prostitution in April and detectives believe he is a predator who may have a trail of victims who have yet to come forward.

That’s also the belief of Stulce’s ex-wife, who accused her ex-husband of raping her on multiple occasions while they were married.

He was convicted on domestic violence charges in 1998 but could be facing additional sexual assault charges since his ex-wife contacted McKinney Police last week.

Melissa Keller, who agreed to be identified, now lives in California and over the phone said her ex-husband raped her while they lived in McKinney in 2007.

“He likes to hurt women, that’s his pleasure.  All I can say is that over the course of our marriage, things seemed to escalate, it just got worse and worse. He was convicted in California for raping me.  He got two years so he spent one year in jail. He’s just a very, very sick man,’ said Keller.

McKinney Police have brought in the FBI to help gather evidence in this widening investigation.

“We did have a feeling that there would be more victims out there so the coverage is bringing results,” said Kim Malolepszy, McKinney Police Deputy Chief.

Stulce has a bond of $200,000.

McKinney Police say some of the women contacting them were able to get away before they were attacked.