FBI investigators suspect the wife of the Orlando gunman, Omar Mateen, might have been aware that he was plotting an attack, and the agency is trying to determine her level of involvement, a senior law enforcement official said Tuesday.

The wife, Noor Zahi Salman, told the FBI that she had driven him to the Pulse nightclub at some point before the attack and that she had also been with him when he purchased ammunition, the official said. But she also said she had tried to talk him out of waging an attack, the official said.

Her statements were first reported by NBC News.

“There’s an indication that she was with him in certain parts of the process, and we’re sorting through it,” said the official, who spoke on the condition of anonymity because the investigation is at an early stage. “We don’t know what’s true and what’s not.”