Butler police Monday arrested a 20-year-old city man on charges he sexually assaulted a 15-year-old girl in July.

Chandler S. Weltner, who is being held in the Butler County Prison on $25,000 bail, faces several felonies in the case.

Police began investigating the case June 29 after receiving a ChildLine Report of suspected child abuse that allegedly happened earlier that month.

The girl was initially interviewed by a Butler County Alliance for Children staff member, and admitted she met Welter in June when he sent her a Facebook message, according to court documents.

In early July, the child recounted, she went to the defendant’s home “to hang out,” a police affidavit said.

The two eventually started kissing and they removed their clothing before having intercourse.

“She added that she was not forced and consented to the conduct,” documents said.

The girl told investigators that she and Weltner had sex two more times that month. She also advised that she informed him of her age after their first encounter.

Butler police Capt. David Dalcamo, the investigating officer, interviewed Weltner at the station Sept. 10.

He admitted he had sex three times with the girl at his home in July, documents said.

“He stated that he did not know how old the victim actually was until her mother showed up at (his) residence and advised him,” the affidavit said.

Weltner was arraigned Monday on two counts of involuntary deviate sexual intercourse and three counts each of statutory sexual assault and corruption of minors, all felonies.

He also is charged with a misdemeanor count of indecent assault.

A preliminary hearing was not immediately set.