Carlos Greene, the Maryland man who crashed an SUV on the East Front plaza and took Capitol Police officers on a wild chase through the Capitol in September 2006, will head to prison for at least five years after pleading guilty today to several charges stemming from the incident. Greene’s foray through several floors of the Capitol while carrying a small pistol and crack cocaine was the worst breach of Congressional security in more than eight years. The incident led then-Capitol Police Chief Christopher McGaffin to issue an apology after several Members of Congress criticized the department for allowing Green to enter the building. In an appearance before U.S. District Judge Deborah Robinson this afternoon, Greene, 21, pleaded guilty to possession of cocaine, unlawful possession of a firearm and ammunition, and assaulting a police officer and resisting arrest. According to a press release from Jeffrey Taylor, the U.S. attorney for the District of Columbia, Greene will face a mandatory minimum prison term of five years when he is sentenced in District Court on Sept. 27. . Senate Sergeant-at-Arms Terrance Gainer, who also serves as chairman of the Capitol Police Board, welcomed news of the guilty plea Thursday afternoon. “The case was put together very well even if we tripped up a bit in that he got as far as he did,” said Gainer, a former chief of the Capitol Police who was sworn in as Sergeant-at-Arms at the beginning of the 110th Congress and was actually working in the private sector at the time of the Greene incident. “This demonstrates the good relationship the police have with the prosecutors. This guy saw the evidence against him and pled. … The good news is that he will be off the street for a number of years.” Greene’s bizarre chase began at around 8 a.m. on Sept. 18, 2006, when he drove a silver sport utility vehicle through a Capitol Visitor Center security checkpoint at First Street and Maryland Avenue Northeast, crashed into the base of a CVC skylight and entered the Capitol after ignoring shouts to stop from Capitol Police officers. After making his way through four floors of the Capitol during a three-minute chase, Greene eventually found himself at the House Flag Office, where a struggle ended with Greene held in a bear hug by an Architect of the Capitol employee until police officers arrived on the scene. According to the the release from the U.S. attorney’s office, “Green resisted arrest and struggled with the officers, at which time a small clear plastic bag containing fifteen brown rock-like substances fell from Greene to the ground.” That substance was later determined to be approximately 10 grams of crack cocaine. In his pants pocket, officers also found a loaded Derringer .22 caliber pistol.