Hoping to clearly demonstrate the exact types of weapons they're seeking to ban, congressional Democrats displayed 10 military-style assault weapons Thursday at one of the most elaborately-staged news events in recent Capitol Hill history.

Sen. Dianne Feinstein( D-Calif.) speaks during a news conference on Capitol Hill in Washington, Thursday, Jan. 24, 2013, to introduce legislation on assault weapons and high-capacity ammunition feeding devices. (Manuel Balce Ceneta -- Associated Press)

But considering the District of Columbia's ban on assault weapons, where did they get the guns and how did they get them in the building?It's an especially pertinent question considering the recent controversy involving NBC's "Meet the Press," which displayed a large ammunition magazine in its District studio during a recent episode without the consent of the D.C. Police Department. The incident prompted an investigation, but no charges were filed.

In the case of congressional Democrats, the office of Sen. Dianne Feinstein (D-Calif.) asked D.C. Police to provide them with weapons they could display at their event. Assault weapons in the custody of police are permitted in D.C., according to Feinstein spokesman Brian Weiss.

Following the event, Feinstein told reporters the weapons were police evidence, but at the time she declined to say from which police agency.

"Senator Feinstein’s office coordinated this process with all relevant agencies and departments to make certain all applicable laws were followed," Weiss said in a statement.

U.S. Capitol Police and the Senate Sergeant at Arms inspected the weapons to ensure they were inoperable before they were permitted inside the Dirksen Senate Office building for the event, according to Weiss and Capitol Police spokesman Shennell Antrobus.

"We routinely work with our stakeholders during the course of their duties, and within the framework of the various applicable laws, to ensure the weapons brought in for hearings are done so in a safe manner," Antrobus said in an e-mail.

Thursday's 75-minute event also included remarks from Democratic co-sponsors of the assault weapon ban, religious and law enforcement leaders and brief statements from family members of victims of recent mass shootings and some survivors of those same incidents.