Facebook's biggest conference of the year was overshadowed by the fatal shooting in Cleveland that was uploaded to the social media giant.

At the Tuesday conference in California, Facebook founder and Dobbs Ferry native Mark Zuckerberg expressed his condolences to the family of a Cleveland man whose death was posted on the social media site on Easter. Facebook has come under fire for leaving up the disturbing video for about two hours before it was taken down.

Police say 37-year-old Steve Stephens killed Robert Godwin in Cleveland, as the grandfather was walking home from an Easter meal. Stephens then posted video of the shooting on Facebook. On Tuesday, Stephens shot and killed himself after a short chase with state police in Erie, Pennsylvania.

Zuckerberg said Tuesday that Facebook has a responsibility to make sure the site is not used a tool for spreading video of violent acts.

Matthew Miraglia is a former Scarsdale police detective who now teaches Homeland Security courses at Mercy College. He says the video of Godwin's death is a double-edged sword.

"From a law enforcement and apprehension perspective, having a person's face out there no longer makes them invisible," he says.

Cleveland's police chief said the video was not something that should "have been shared around the world."

Investigators said Godwin was the only victim so far linked to Stephens, despite his claim on Facebook that he killed over a dozen people.