Authorities in Las Vegas now believe Stephen Paddock planned to evade authorities after Sunday night’s mass shooting, and they are not ruling out the possibility that the 64-year-old had help plotting the shooting that killed 58 people and wounded more than 500.
“Do you think this was all accomplished on his own?,” Las Vegas Metropolitan Police Department Sheriff Joseph Lombardo said during a Wednesday press conference, referencing the dozens of weapons recovered from the shooter’s room on the 32nd floor of the Mandalay Bay Resort and Casino. “You’ve got to make the assumption he had to have some help at some point.”
Since Sunday night, details about the shooting at the Route 91 Harvest country music festival have trickled out slowly. At this point, investigators are still trying to determine a motive for the deadliest mass shooting by a single gunman in modern U.S. history.
Initially, investigators had dubbed the shooter a “lone wolf” killer, saying he acted alone.
Lombardo also told reporters evidence collected from the shooter’s room suggests he intended to survive and escape, though Lombardo did not specify what that evidence was.
Also on Wednesday, Lombardo said the shooter had rented an apartment in Las Vegas two weeks ago through Airbnb and believe he chose that location because of its proximity to another music festival in Las Vegas last weekend.
The shooter fatally shot himself on Sunday night as tactical units started closing in, authorities have said.
On Wednesday, the shooter’s girlfriend, Marilou Danley, returned to the United States following a trip to the Philippines. Local and federal law enforcement officials spent hours interviewing Danley, who insisted Wednesday through her attorney that she had no prior knowledge of the impending attacks.
“It never occurred to me in any way whatsoever that he was planning violence against anyone,” the statement reads. “He never said anything to me or took any action that I was aware of that I understood in any way to be a warning that something horrible like this was going to happen.”
According to Lombardo, Danley remains the only person of interest in this case.
Lombardo said it was possible that the shooter, who spent the eight hours before the killings gambling, was “working out all of this on his own” before reaffirming his suspicion that he did not act alone. “It would be hard for me to believe that” he had no help, Lombardo said.
Additionally, Lombardo said that a security guard had helped locate the shooter on the 32nd floor just minutes after he opened fire on the crowd of concertgoers. The shooter, according to Lombardo, set up several surveillance cameras outside his room to monitor the hallway.
The shooter allegedly shot nearly 200 rounds through the door, injuring the guard.
This article originally appeared on PEOPLE.