Police placed the U.S. Capitol on lockdown "as a precautionary measure" after an apparent suicide shooting near the building's West Front on Saturday. In their initial statement, authorities said only that the suspected shooter had been "neutralized."

Additionally, police are reportedly investigating a "potential explosive device" found at the scene. According to NBC News reporter Pete Williams, the suspected gunman shot and killed himself and the suspicious package is the man's briefcase.

UPDATE 2:40 p.m.: Officials speaking to NBC News have confirmed that the shooting appears to be a suicide and the suspicious package is the gunman's suitcase. One federal official told the network "there are no indications at this point of terrorism."

UPDATE 2:50 p.m.: In addition to the suitcase found nearby, ABC News reports that the shooter was wearing a backpack and had a sign taped to one of his hands. A bomb disposal team is reportedly preparing to investigate the suitcase.

UPDATE 3:00 p.m.: According to WTOP, a Capitol Police spokesperson has confirmed that the suspected gunman was "neutralized" by a self-inflicted gunshot wound.

UPDATE 3:20 p.m.: An unverified eyewitness on Twitter reports the shooter's sign read "tax the other 1/4 or something like that."

UPDATE 4:55 p.m.: The lockdown at the U.S. Capitol has been lifted.

UPDATE 5:20 p.m.: At a press conference Saturday afternoon, Capitol Police Chief Kim Dine said today's incident had no connection with terrorism and that the suspect's sign had a "social justice" message.

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