HIROSHIMA, Japan — Japanese police confirmed Monday that they may recommend a Japanese man already in custody for firearms violations in connection with the shooting of a U.S. sailor also be charged with attempted murder.

Tomoyuki Matsumoto, 37, turned himself in, claiming he shot U.S. Navy Petty Officer 3rd Class Eric S. Heinze, police have said.

Matsumoto, of Minato ward, was accused Saturday of attempted murder and an act of violence, according to Hiroshima Higashi police. He was arrested last month for violating the firearms and sword control law after he surrendered with a handgun to police, claiming he shot the sailor, police said.

Matsumoto told police he shot Heinze because the sailor crossed in front of his car and he wanted to teach the sailor a lesson, the law officers said.

Heinze and two other sailors were walking through a popular entertainment district in Hiroshima the morning of Oct. 26 when he was shot, police said. He underwent surgery to remove the bullet from his left waist area and was hospitalized for a few days.

The two other sailors were not injured.

A urine test showed traces of a stimulant in Matsumoto’s system, police said, declining to provide further details.

The shooting remains under investigation.