Sean Ernest Ruis, a 43-year-old man in Eaton County, Michigan was shot and killed by a police officer, Buzzfeed News reported. Ruis had reportedly stabbed a 77-year-old man after he was asked to wear a face-mask inside a store.

Ruis was refused service by the Quality Dairy store for not wearing a mask. After stabbing and injuring the old man, he fled the scene in a car.

In a statement, police sheriff Tom Reich said he believed that Ruis intended to “violently attack” a sheriff’s deputy after his car was intercepted. In the officer’s body camera video that was released by Eaton County Sheriff’s office, the deputy is heard telling Ruis to “drop the weapon”.

“She acted in defence of her life,” Reich was quoted as saying by BuzzFeed News.