Saturday afternoon when an active shooter entered a Buffalo supermarket planning to kill as many people as possible, he wasn't counting on a retired police officer working security.

Retired Buffalo Officer Aaron Salter, 55, was the first to defend lives and engage the shooter when he entered the Tops market around 2:30 p.m., the Buffalo News reports.

Police Chief Joseph Gramaglia called Salter a "hero" and said the retiree fired multiple rounds at the attacker and managed to hit him, but the bullets did no damage because of the shooter was reportedly wearing body armor.

Salter was one of 10 people killed in the attack. His heroism likely delayed the killer and saved lives.