A 38-year-old sex offender who was on GPS monitoring has been charged with sexually assaulting a 12-year-old Milwaukee girl at gunpoint in a vacant city-owned house.

Collins Lamon Jacobs faces charges of first-degree child sexual assault, kidnapping and child enticement, all felonies.

The assault occurred about 9:30 a.m. Dec. 1 in the 3000 block of N. 27th St. and Jacobs was at that location at that time, prosecutors say.

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According to the criminal complaint:

The girl ran away from home the night of Nov. 30. Her aunt saw her the next day standing outside the house with a man, later identified in a photo line-up as Jacobs.

Her aunt saw Jacobs drag the girl by the hood of her jacket toward a gas station and she yelled to her niece. The girl ran to her, saying Jacobs had just raped her.

The girl told investigators she had run away and Jacobs approached her and asked how old she was. The girl said she was 12. Jacobs went away, but then returned and asked if she wanted "to go somewhere with him for $100."

The girl told him no, and Jacobs dragged her to the vacant house at gunpoint. They went inside through a back door.

They girl said Jacobs forced her to perform oral sex with a gun to her head, saying if she did she would be able to go home.

Jacobs is on the lifetime sex offender registration with GPS monitoring, which showed he was at the vacant house about 6:30 a.m. Dec. 1. He was convicted of third-degree sexual assault in 2008 and second-degree section assault of a child in 1999, records show.

In August, he was charged with violating the sex offender registry by failing to comply with reporting requirements in January. He was released on his signature in that case and was due in court for a plea and sentencing hearing Dec. 15.

Online court records show Jacobs was charged on Nov. 2 with violating a domestic abuse injunction when he contacted an ex-girlfriend, a misdemeanor, and a warrant was issued for his arrest.

Milwaukee police did take a report Nov. 1 about that incident and tried to find Jacobs that day without success, department spokesman Sgt. Tim Gauerke said.

But Milwaukee police records indicate the case was "no processed," meaning prosecutors did not issue charges in the case and officers therefore were not aware of any warrant, he said.

On Nov. 28, three days before the assault in the vacant house, he was charged with another violation of the sex offender registry, and another arrest warrant was issued.

That was not a Milwaukee police case and city officers were not aware of any warrant being issued, Gauerke said.

After the assault, on Dec. 5, Jacobs was charged with felony bail jumping and violating the domestic abuse injunction again after his ex-girlfriend reported unwanted contact from him Nov. 21 and called police about it the same day.

Police records show officers first took that case to prosecutors on Nov. 27 and prosecutors decided not to issue charges, Gauerke said.

Prosecutors reviewed the case again on Dec. 4 and issued the charges and warrant, he said.

Jacobs was arrested Thursday by Milwaukee police officers after receiving information about his location from the state Department of Corrections. He was charged Friday in the sexual assault of the 12-year-old girl and taken to Milwaukee County Jail.

Corrections officials told Milwaukee police Jacobs was inconsistently charging his GPS, meaning his location was unknown during those times but began charging it again one day before the sex assault, Gauerke said.

The Milwaukee County district attorney's office and the state Department of Corrections did not respond to questions about Jacobs' history Tuesday afternoon.

The vacant house where the assault was reported has been the subject of a half-dozen complaints this year, ranging from graffiti to dumping to high grass, city records show.

On Nov. 2, city employees noticed a door on the house needed to be secured and a request was sent to the board-up vendor.

The vendor went to the site and sent the city a photo of a vacant lot across the street, reporting the request was completed and the property had been demolished, city officials have said.

After the sexual assault was reported, the house was boarded up and secured.