Las Vegas police on Tuesday (October 3) said that Stephen Paddock, the retiree who killed 58 people in the worst mass shooting in modern U.S. history, strafed the concert crowd with bullets for nine to 11 minutes before taking his own life, and had set up cameras inside and outside his hotel suite so he could see police as they closed in on his location.

Authorities said that Paddock left an arsenal of 49 guns but no clear clues as to why he staged the attack on a crowd of 20,000 from a 32nd-floor window of the Mandalay Bay hotel. More than 500 people were injured, some trampled.

The investigation into the motives of the mass shooting turned to the gunman’s girlfriend in the Philippines, where she turned up after the massacre, authorities said. Law enforcement authorities were hoping to obtain some answers from a woman identified as Paddock’s live-in companion, Marilou Danley, who they say was a “person of interest” in the investigation.

Danley, an Australian citizen reported to have been born in the Philippines, had been sharing Paddock’s condo at a retirement community in Mesquite, Nevada, about 90 miles (145 km) northeast of Las Vegas, according to police and public records. Investigators were examining a $100,000 wire transfer Paddock, 64, sent to an account in the Philippines that “appears to have been intended” for Danley, a senior U.S. homeland security official told Reuters on Tuesday.