Police say a Las Vegas Strip sidewalk was crowded with people viewing a fountain show at the Bellagio resort when an officer answering 911 calls arrived and fired twice at a man wielding a gun.

Undersheriff Kevin McMahill showed video Tuesday of the suspect, 20-year-old Khaleal Black, pointing an empty snub-nosed revolver at people and pulling the trigger Friday evening.

Black wasn't wounded, but he fell to the sidewalk and was arrested. McMahill says the officer's two shots ricocheted off concrete pillars, one bullet grazing the leg of a 4-year-old boy on his father's shoulders.

The other zipped through clothing of a homeless man sitting nearly 100 yards away. He wasn't wounded.

McMahill says Black had a history of mental health issues and suicide threats. He's due in court Wednesday.