WASHINGTON (AP) — A man clad in black who was obsessed with President Barack Obama pulled his car within view of the White House at night and fired shots from an assault rifle, cracking a window of the first family’s living quarters while the president was away, authorities said about their still-developing investigation.

The U.S. Secret Service found two bullets had hit the White House and agents caught up with Oscar Ramiro Ortega-Hernandez in Pennsylvania on Wednesday after a four-day search. Police arrested the 21-year-old Idaho man at a hotel after a desk clerk recognized his picture. Ortega was scheduled to make his first appearance at 2 p.m. Thursday in federal court in Pittsburgh and many questions remained about his motive and background.

Authorities are investigating the man’s mental health and say there are indications he believed attacking the White House was part of a personal mission from God, according to two different law enforcement officials who spoke with The Associated Press. There are also indications the man had become obsessed with Obama and the White House, according to the officials, who spoke on the condition of anonymity because the investigation is ongoing.

Shots were fired at the building Friday night. Agents discovered Tuesday that one of the two bullets hit the exterior and a second cracked a window on the second floor residential level, just behind the rounded portico visible from the south side of the White House.

That bullet was stopped by protective ballistic glass. The window that was hit is in front of the so-called Yellow Oval Room, which is in the middle of the family’s living quarters.

Obama and his wife Michelle were on a trip to California and Hawaii at the time of the shooting. The president has since traveled on to Australia on a nine-day Asia-Pacific tour. The Obamas were in California without daughters Malia and Sasha, but the White House had no immediate comment on the shooting or who may have been home at the time.

Investigators believe Ortega fired the rifle from his vehicle Friday, according to an official with knowledge of the investigation. Gunshots were reported that night on Constitution Avenue about 9:30 p.m. Soon after, U.S. Park Police found an abandoned vehicle, the assault rifle inside it, near a bridge leading out of the nation’s capital to Virginia. The car led investigators to Ortega, and they obtained a warrant for his arrest Sunday, officials said.

This is not the first time the White House has come under attack.

In the last 40 years, the landmark has faced threats ranging from a stolen helicopter that landed on the grounds in 1974 to a man who wielded a sawed-off shotgun on a sidewalk outside in 1984. In 1994 alone, there were five threats including a plane crash on the lawn and a suspected drive-by shooting. Another man fired at least 29 rounds from a semiautomatic weapon, with 11 striking the White House. Ortega is from Idaho Falls, Idaho, and was reported missing Oct. 31 by his family. A message left for Ortega’s mother Wednesday at an Idaho Falls restaurant where she works was not returned. Phone listings for family members in the city were disconnected.

Ortega has an arrest record in three states but has not been linked to any radical organisations, U.S. Park Police have said.