Jared Loughner, the man accused of opening fire on a crowd of people in Arizona and killing six of them and critically injuring Congress member Gabrielle Giffords, will appear in court on Monday, according to the federal complaint against him.

According to CBS News, the 22-year-old may face the death penalty for the incident.

Among those who died, were a 9-year-old girl, a federal judge and several others.

Rep. Giffords is fighting for her life and was placed into a medically-induced coma after she was shot in the head.

The attorney who defended Oklahoma City bomber Timothy McVeigh and Unabomber Ted Kaczynski may represent Loughner.

President Barack Obama led a moment of silence at 11:00 a.m. Monday for the victims’ families.

Investigators said that Loughner acted alone but has refused to speak with them.

"This individual is a very troubled individual … who is a loner," Pima County Sheriff Clarence Dupnik told ABC. "We're still actively pursuing any activities that he might have been involved in. I'm not aware of any ties he had to any group."

Loughner posted a series of incomprehensible posts on Youtube that claimed everything from police officers to Pima Community College, a school he was suspended from, is unconstitutional. One of his posts said people aren’t literate and aren’t aware of the government’s “mind control and brainwash methods.”

His lone favorite video is a scene of a hooded, masked individual wearing what appears to be black plastic pants lurching to a shredded American flag, and then burning it. The song “Bodies” by Drowning Pool plays in the background.

The American flag video, posted by user Starhitshnaz, appeared to have been made by Loughner. He used similar rhetoric in a post below the video. Also, the Youtube channel is the same red-black color as his own.

According to people who knew Loughner, he had erratic behavior.

"He was one of the last kids to come in, and he sat down and almost immediately started laughing to himself in a way that was just kind of creepy," said Alex Kotonias, 20, who had a seat behind him at Pima College, told the Associated Press.

"And then, as soon as the teacher started going over the syllabus,” Kotonias added, “he had this outburst out of nowhere, didn't even raise his hand, and started asking the teacher some sort of weird questions about whether he believed in mind control."

In September, he was suspended from the school and the college sent two police officers to his parents’ home.

Several months later, police told AP that he went to Sportsman’s Warehouse in Tuscon and bought a Glock 9mm handgun that he allegedly used in the shooting.