Shawn Begolly, right, walks to federal court in Pittsburgh for a detention hearing for his son, Emerson Begolly with his wife, Tiffani, center, and a public defender investigator, on Thursday.

PITTSBURGH — A man who posted online pro-terrorist songs and statements and is charged with biting FBI agents who struggled for his concealed gun during a confrontation will be allowed to remain free pending trial, provided he’s in a halfway house, a judge said Thursday.

Still, the federal magistrate said Emerson Begolly, 21, must remain jailed until late today so Assistant U.S. Attorney Margaret Picking has time to file an emergency appeal.

Picking argued that Begolly’s posts using the name Asadullah Alshishani, some in the form of poems or Islamic chants, are so alarming he must be jailed. Some posts criticized the United States as “AmeriKKKa” and praised terrorism, including Swedish suicide bomber Taimour Abdulwahab al-Abdaly.

Begolly was arrested Tuesday by two FBI agents in New Bethlehem, Clarion County.

“This young man is similar to Dr. Jekyll and Mr. Hyde — explosive at one minute and docile the next,” Picking argued to U.S. Magistrate Judge Ervin Swearingen at a three-hour hearing Thursday. “It’s those explosive moments that concern the government, your honor.”

But federal public defender Marketa Sims suggested the government’s claims were overblown.

“I’ve never yet in 21 years practicing law seen anybody detained by poem,” she told the judge, saying the government never said what crime it believed was committed by Begolly.

All parties agree Begolly is a socially inept loner who has an IQ of 160 but doesn’t know how to drive. Begolly, who suffers from a form of autism, has taken college courses online since the eighth grade and until recently attended a satellite campus of Penn State University, which has taken steps to suspend him.

When he wasn’t in school, he was online or taking walks — often carrying a gun, sometimes the AK-47 assault rifle he bought legally last year, his father, Shawn Begolly, testified Thursday.

The agents, with his mother’s help, found him sitting alone in the front seat of a car parked at a fast-food restaurant when one agent opened the vehicle door. That’s when Begolly screamed and reached into his jacket, at which time both agents tried to keep him from grabbing what they believed was a gun, a criminal complaint said.

“Agents attempted to control Begolly, Begolly bit both agents and drew blood,” the complaint said, adding that agents then found a loaded 9 mm handgun inside his jacket, with the safety in the off position and one round in the chamber.

Begolly, who had never been arrested before, is charged with assaulting, resisting or impeding federal officers and with possessing a firearm during a crime of violence.

Sims said after the hearing that Begolly’s birth mother, Joan Kowalski, was “devastated” to learn her son faces prison if he’s convicted.

An agent who knew Kowalski contacted her and offered to get her son psychiatric help, saying the FBI was concerned about his Internet posts, an FBI agent testified. She agreed to call her son and tell him his grandmother was near death so he would allow her to pick him up at his father’s farm.

She parked at a Burger King and went inside so that the two FBI agents could confront her son.

FBI Agent Michael Christman testified that the FBI had concerns about Begolly’s alleged “anti-Semitic views.”

The agents took Begolly to a mental health facility where his mother signed a commitment form. Because the facility was too crowded, he’s been in the psychiatric unit at the Allegheny County Jail.