Perhaps the most serious breach occurred on September 19, 2014, when Omar Gonzalez climbed over the north fence and made his way deep into the White House.
A California man charged with jumping the White House fence over the weekend is due back in court.
Tran made his first court appearance in Superior Court of the District of Columbia this afternoon on a charge of entering or remaining in restricted grounds while using or carrying a risky weapon.
The backpack was found to be free of any hazardous materials, according to the Secret Service statement.
This article has been updated to include President Trump's comments. He said in the letter that he had information relevant to the issue of "Russian hackers", according to charging documents.
He was not in any danger during the incident, CNN reported, citing an unnamed source.
This was the first White House intrusion under President Trump. Omar Gonzales walked through the North Portico door with a folding knife in his trousers pocket in 2014. He was also armed with a three and a half inch folding knife.
On Thanksgiving in 2015 the Secret Service apprehended Joseph Caputo, from CT, on the North Lawn. The intruder was taken into custody without incident.
Trump earlier thanked the Secret Service and commended the agents for apprehending the intruder.