Theodore Howard, 48, of Chicago, was arrested Sunday in the 100 block of West 103rd Street by the Chicago FBI Joint Terrorism Task Force, according to a release from the FBI. 

He was charged in a superseding indictment with interference with the operation of a train and violating federal firearms statutes, both felonies, the release said.

Telly S. Virgin was previously arrested in the case in October 2007. He has pleaded not guilty to the charges and is awaiting trial, court records said. An Oct. 23 status hearing has been set for Virgin's case.

According to the release, Howard allegedly hired Virgin to kill his ex-wife, an engineer on Metra's South Shore line.

According to columns by Mary Mitchell in the Chicago Sun-Times, Howard had allegedly abused and stalked his ex, Andrea Brown, who had taken out protection orders against him.

Someone shot at a Metra train Brown was supposed to be operating on June 6 and June 8, 2007. Brown had switched shifts on June 6 to watch her son's baseball game. No one was injured in either shooting.

"I had no idea what was going to happen," the Metra engineer who was operating the train that day told Mitchell. "I noticed a gentleman standing on the platform real close to the edge. What alerted me was he had on a winter jacket and it was 72 degrees out. Then his hand went in his pocket and that's when I saw a silver-plated gun. He started shooting at point-blank range."

Howard was ordered held without bond by U.S. Magistrate Judge Nan Nolan on Monday and is scheduled to appear before U.S. District James Moran at 9 a.m. Tuesday in U.S. District Court in Chicago, the release said.

Howard and Virgin are charged in a six-count indictment and if convicted, face up to 50 years in prison each, the release said.