Article will continue after advertisement

WARNING: This is very hard to watch.

Police in New York City have released video that shows a man casually walking beside a senior citizen and then brutally punching him in the face — a blow that killed the elderly man.

RELATED: This teenager is going to jail after punching an elderly man

Patrick Gorman, 64, was walking about midnight in the borough of Queens, NY., when the apparently unprovoked attack happened. After Gorman takes the punch, the video shows him trying to get up before collapsing to the ground.

He died a few hours later, according to the television station WPXI.

The attack happened in June, but police are releasing the video now in hopes of finding the suspect.

Let’s hope they do.