Jared Lee Loughner wrote "Die, bitch" in a note found at his home, a sheriff's official told The Associated Press on Tuesday.

Investigators believe Jared Loughner's handwritten message was a reference to Giffords, said Rick Kastigar, the Sheriff's Department's Pima County chief. It was found in a safe alongside other notes, including ones saying, "I planned ahead," "My assassination" and the name "Giffords."

Authorities also revealed other new information about the hours leading up to the Saturday shooting that killed six people and injured 13 others, including Giffords. That morning, Jared Loughner's father saw him take a black bag out of a car trunk, Sheriff Clarence Dupnik told the AP.

The father approached Loughner, and he mumbled something and took off running, Dupnik said. The father got in his truck and chased his son as he ran off on foot.

The Associated Press