Butler police Thursday evening arrested a homeless man who they say raped a 14-year-old girl at a city house.

Nicholas C. Feitl, 29, is suspected of sexually assaulting the teenager after a weekend party in August at her mother’s home.

Officers had been looking for Feitl all day after obtaining an arrest warrant. He was nabbed shortly after 7 p.m. inside the Butler Public Library on North McKean Street.

He is being held in the Butler County Prison on $100,000 bail.

Feitl is charged with rape, statutory sexual assault, involuntary deviate sexual intercourse, two counts of aggravated indecent assault, and corruption of minors, all felonies.

He also faces misdemeanor charges of child endangerment and six counts of indecent assault.

The victim told an investigator that she encountered Feitl at a party at her mother’s house earlier that month, police said.

While not certain of the date, she recalled that the party, which was attended by other adults and children, happened on a Saturday.

She knew the defendant that evening only by the name “Nick,” according to court documents.

After the party ended, the girl found herself alone with Feitl in the dining room. She said he touched her suggestively while she was lying on a bench.

She told him, “No, please don’t,” a police affidavit said, “and he stopped.”

But when the teenager moved into the living room, where she laid down on a mattress to go to sleep, the defendant followed her. Later, he again touched her in a sexually explicit manner.

Again, documents said, she rebuffed his advances a second time and then a third time.

But at some point, the girl said, Feitl forced himself on her, sexually assaulting and raping her.

The alleged attack, according to the teen’s account, awakened a younger girl who also had been asleep in the living room.

When he heard the other girl, the defendant stopped. The victim told investigators that she went into the bathroom and advised Feitl to leave or she would tell her mother what he did.

Following a brief argument, she said, he left.

District Judge William Fullerton on Thursday issued an arrest warrant for the suspect. But since Feitl has no known address, police admitted not knowing his whereabouts.

Detectives said he previously was known to visit a wooded camp frequented by homeless people in the city.

Police, in hopes of tracking down the suspect, posted a photograph of him on the department’s Facebook page. That move apparently paid off.

An employee at the Butler library called 911 at 7 p.m., reporting that Feitl was there. The employee knew he was wanted by police, Lt. Detective Anthony Fatta said.

Officers got to the library and were directed to the second floor.

“He was seated at a computer terminal,” Fatta said. He was arrested without incident.