CHICAGO (AP) — A teenager charged with terrorism in what U.S. prosecutors call an attempt to bomb a Chicago bar has pleaded not guilty to new charges that he tried to have an FBI agent killed.

Adel Daoud looked relaxed as he entered a federal courtroom for his arraignment Friday. The 19-year-old smiled, waved to his parents and fist-bumped his attorney, asking, "What's up, man?"

Defense attorney Thomas Durkin later told reporters that Daoud's cheerful demeanor raises questions about his psychological state and whether he appreciates the seriousness of his situation, "which is part of the problem."

Durkin says allegations that Daoud tried to arrange the murder of a federal agent who participated in the sting that led to his 2012 arrest are "laughable." Court documents say the plot was intended to prevent the agent from testifying.

A spokeswoman for the U.S. attorney's office, Kimberly Nerheim, declined to comment Friday.

Daoud in October pleaded not guilty to a terrorism charge. According to court documents, an undercover agent pretending to be a terrorist provided the teen with a phony car bomb and watched him plant the bomb and press a trigger.

He is now charged with solicitation of murder, a charge that carries a maximum 20-year prison term. If convicted of terrorism, Daoud faces life in prison.

Durkin says the new charges are based on the word of a street gang leader-turned-jailhouse snitch who shared a cell with Daoud. The attorney asserted that such informants are notoriously unreliable.

"If my client's a terrorist, I'll eat my hat," Durkin said.