President Donald Trump reacted to news the FBI failed to uncover a motive for the mass-shooting in Las Vegas.

“It was just a — just a terrible thing. They were unable to find a real reason other than, obviously, he was sick and they didn’t know it,” Trump said about the shooter in an interview with the Daily Caller.

The FBI Behavior Analysis Unit on Tuesday shared additional information about the investigation, concluding there was “no single or clear motivating factor” for the shooter’s actions.

The president said learning the motive was important in order to prevent other mass shootings in the future.

“I was a little surprised and a lot disappointed that they weren’t able to find the reason,” he said. “Because you’d like to find a reason for that.”

The president said it was “very interesting” when asked by the Daily Caller to compare the level of FBI resources used to investigate Russian attempts to affect the 2016 election.

“You’re talking about, I guess they’re well over 30 million dollars now on this Russian collusion hoax, and everybody knows it’s a hoax,” Trump replied. “They’ve spent all this money. Nothing. … That is very sad.”