Mayor says her comments were made in "frustration and anger."
The plot reportedly involved a Saudi national and two Syrians.
It was unclear whether the gunfire was related to the protests.
An activist was seemingly plucked off the streets in full view of news cameras.
The findings come one day after the Supreme Court heard arguments in same-sex marriage cases.
Obama said a visit now, however, would take "assets out of where they need to be."
Rep. Elijah Cummings said "opportunists took advantage of a kind of chaotic situation."
Hillary called the situation in Baltimore “heartbreaking” during a fundraiser.