LAS VEGAS — The Las Vegas gunman transferred $100,000 to the Philippines in the days before the attack and even set up cameras inside the peephole of his high-rise hotel room and on a service cart outside his door, apparently to spot anyone coming for him, authorities said Tuesday.

Investigators are taking a harder look at the shooter’s girlfriend and what she might have known about the attack at a country music festival, with the sheriff naming her a “person of interest” and saying the FBI is bringing her back to the U.S. on Wednesday for questioning.

Authorities are trying to determine why Stephen Paddock killed 59 people in the deadliest mass shooting in modern U.S. history.

They have been speaking with girlfriend Marilou Danley, 62, who was out the country at the time of the shooting and in the Philippines on Tuesday, and “we anticipate some information from her shortly,” Sheriff Joseph Lombardo said.

Lombardo said he is “absolutely” confident authorities will find out what set off Paddock, a 64-year-old high-stakes gambler and retired accountant who killed himself before police stormed his 32nd-floor room.