WASHINGTON (WJZ)– The FBI stops a suicide bomber in his tracks, halting his alleged plan to blow up the U.S. Capitol.

Kai Jackson talks to a Maryland congressman on the front lines of the undercover sting.

FBI officials describe Amine el Khalifi as a lone wolf constantly under surveillance. But a Maryland congressman said that were it not for tips, el Khalifi could have been deadly.

Amine el Khalifi was arraigned in federal court in Alexandria, Va. Friday afternoon. The Moroccan man was arrested in a Washington, D.C. garage Friday morning near the Capitol, the result of a months-long sting operation.

“This is also a trend that has occurred with what we call the lone wolf,” said U.S. Rep. Dutch Ruppersberger (D-Maryland), who is on the House Select Committee on Intelligence.

According to court documents, the 29-year-old was wearing a vest “containing what el Khalifi believed to be a functioning bomb” and carrying an automatic weapon. Both had been rendered harmless by authorities.

“It’s very difficult to determine who these lone wolves are, if in fact, we don’t get tips,” Ruppersberger said. “So that’s why it’s important to law enforcement– state local, federal– and individuals, when they see something that looks awry then we need to contact law enforcement officials.”

The FBI says el Khalifi’s initial plan was to attack a restaurant and a military outlet. But last month, he decided to conduct a suicide attack on the U.S. Capitol. He allegedly cased the Capitol for weeks. He planned to bring guns to fend off any police. El Khalifi had planned to detonate the bomb inside the Capitol when it was full of people.

A CBS correspondent and former assistant director of the FBI predicts lots of evidence in court.

“You’re going to see video inside apartments of people handling weapons,” John Miller said. “You’re going to hear voice recordings and video recordings of people in cars. You’re going to see him trying on the suicide vest.”

El Khalifi is charged with attempting to use a weapon of mass destruction against U.S. property. His former landlord said he tried to alert Virginia police a year ago about el Khalifi but his tips were ignored.

A bail hearing is set for Wednesday.