WITI-TV, MILWAUKEE - Police arrest an Oak Creek Realtor, whose next address could be behind bars. Police say Joel Hoffman is responsible for a series of sexual assaults since 2009. The investigation really started after a reported sexual assault of UWM student here in an office campus apartment. Police have linked that crime and two others to Joel Hoffman, who also went by the name Joel Lynch.

31-year-old Joel Hoffman is also known to his neighbors as an alleged sex offender, with at least three victims one of them being 14-years-old. One neighbor says, "I was flabbergasted to see there were more charges against this guy, especially now a 14-year-old young lady that's crazy."

He was arrested at the Suburban Motel on Milwaukee's south side.

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Neighbors who spoke with FOX6 news didn't want to be identified. "As a parent in the neighborhood, it's kind of crazy, this guy. Our granddaughter goes over and plays with his step daughter,[but] I hope they can put him away."

Hoffman faces a spate of charges.

According to a criminal complaint, the first five counts stem from the alleged sexual assault of a UWM student at an off campus apartment. The victim told police she answered a knock at the door thinking it was her roommate, instead she says it was Hoffman wearing blue colored latex or rubber gloves.

He allegedly groped and grabbed her private parts, made her pull down her dress, and threatened her with a knife. The assault ended when the suspect heard the victim's roommate come home.

While investigating that crime, police linked Hoffman to two other assaults. Last March, a 16-year-old girl walking home from school reported the suspect came up from behind her and sexually assaulted her on S. 15th St.

Two officers happened to be walking the beat nearby, and the girl told them where the suspect ran.

Police ended up questioning Hoffman.

Meanwhile, a third victim reported in September that a stalker approached her multiple times on her way home from school. The 14-year-old told police she was propositioned and cornered in an alley, but escaped.

Police say one of the things that linked Hoffman to all these cases is his black Dodge Charger seen at the location of each alleged crime. Hoffman is registered as a sex offender with a previous sexual assault conviction. He's currently being held in the county jail.