Federal investigators are analyzing device’s content, although it is unclear how agency gained access

The FBI has gained access to the phone of the suspected gunman who opened fire on Donald Trump’s rally and is analyzing the device’s contents, the agency stated in a press release on Monday afternoon. The shooting, which killed one audience member and left Trump bleeding from one ear, is being investigated as an assassination attempt.

Authorities have been working to determine the motive behind the attack at Trump’s campaign rally on Saturday, but no clear picture has yet emerged. The gunman, identified as 20-year-old Thomas Matthew Crooks by the FBI, was shot and killed in the incident.

Federal investigators announced on Sunday that they had obtained Crooks’s cellphone, but had issues with bypassing its password protections to access the data within. FBI investigators then shipped the phone to a lab in Virginia, where agents successfully gained access, per the bureau’s press release.