As with the party crashers, the incident was more embarrassing than dangerous, but it raises questions about security procedures at the White House as well as the ability of the Secret Service to thoroughly investigate its own failings.

Recent revelations about a fence-jumper who made it past the front door, another days earlier involving a man with a gun in an elevator with President Obama, and the agency’s handling of a prostitution scandal have critics saying its problems are systemic and go back years.

Two German tourists, a woman and a man toting cameras the White House tour website says are prohibited in the building and on the grounds, managed to circumvent any electronic screening and walk into an open White House gate where tourists completing their tour were exiting.