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.
"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, of Natrona Heights, in western Pennsylvania.
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 eight 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.
Emerson Begolly was arrested Tuesday by two FBI agents in New Bethlehem, about 50 miles northeast of Pittsburgh.
The agents, with his mother's help, found him sitting alone in the front seat of a car parked in 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 9mm 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.
The phone number for Begolly's mother was disconnected Thursday. Shawn Begolly and his second wife, Tiffani Begolly, declined to comment after the hearing.