The Secret Service is stepping up its patrols around the White House after a second security breach in as many days.
In the latest incident, a man walked up to the White House Saturday and was turned away.
The Secret Service says that same man drove through a gated area soon after, and refused to leave.
It comes a day after 42-year-old Omar J. Gonzalez from Texas was arrested for jumping a fence, running across the lawn and inside the North Portico doors.
President Obama and his daughters departed from the South Lawn in Marine One moments before the incident.
The Secret Service initially said Gonzalez was not armed, but the US attorney’s office now says he had a knife.
Gonzalez was charged with unlawfully entering a restricted building or grounds while carrying a “deadly or dangerous weapon”, according to an affidavit released by the US attorney’s office.
He faces up to 10 years in prison, if convicted.