Las Vegas shooter's girlfriend said she handled ammo

The girlfriend of the gunman behind the deadliest mass shooting in modern U.S. history told authorities they would probably find her fingerprints on bullets because she sometimes helped him load ammunition magazines.

An FBI agent tells a judge in warrant documents made public Friday that Marilou Danley wasn't arrested when she returned to the U.S. from the Philippines days after the Oct. 1 shooting, and that she was cooperating with investigators.

Her boyfriend, Stephen Paddock, shot himself dead after firing from a Las Vegas Strip casino into a concert crowd, killing 58 people and injuring hundreds.

The agent says in the Oct. 3 document that there was no evidence at that time of "criminal involvement" by Danley, but that investigators had not ruled out the possibility.

The document says Danley also provided a DNA sample to authorities.

FBI spokeswoman Sandra Breault in Las Vegas said late Friday she could not comment about Danley or the investigation.