The Marin Independent Journal reported Wednesday that Samuel Cutrufelli filed the suit claiming 90-year-old Jay Leone negligently shot him.
Cutrufelli is charged with two counts of attempted murder after Leone was shot in the face on Jan. 3. Police say Cutrufelli was wounded when Leone returned fire.
Leone has vowed to countersue, saying Cutrufelli was the one who busted in his door and shot him before tying his hands with a belt and going through his valuables.
Leoni says he was able to get free and grab a handgun stashed in his bathroom.