The bullets were thought to have been fired during a drive-by shooting that resulted in two bullets hitting the White House. One of the bullets
was found impacted in the ballistic glass of an exterior window on the residential level where the president and his family live.
Police on Wednesday night arrested a 21-year-old Hispanic man in Pennsylvania in connection with the shooting.
Oscar Ortega-Hernandez was arrested by state police at a hotel near Indiana, the Secret Service special agent in charge, Edwin Donovan, said.
Witnesses heard shots and saw two speeding vehicles in the area, in between the White House and the Washington Monument, late on Friday night. An AK-47 rifle was recovered and semi-automatic gun was also involved, a US Park Police spokesman said.
President Obamaand the first lady, Michelle Obama, were in California at the time of the shooting.
Officials could be seen taking photographs of a window on the south face of the executive mansion yesterday.
The probe has not yet "conclusively connected" the bullets found on the White House grounds to Friday's incident.
Ortega is from Idaho Falls, Idaho, and was believed to be living in the Washington area. He was reported missing Oct 31 by his family. He has an arrest record in three states but has not been linked to any radical organisations, US Park Police said.
Mr Ortega is described as a 5'11, white Hispanic male of medium build, with several distinguishing tattoos – including three dots on his right hand, his name across his back and the word Israel tattooed on his neck.
"As the investigation unfolded, the US Park Police located a vehicle in the 2300 block of Constitution Avenue," the US Park Police said in an earlier statement.
"Evidence in the vehicle led to us obtaining an arrest warrant for Oscar Ortega."