A security guard was arrested and charged with murder after she shot a man who allegedly spat on her inside an IHOP in Center City, Philadelphia police said on Monday.

The shooting happened shortly before 11:15 p.m. on Saturday at the IHOP on 13th and Walnut streets. Officers responded to the restaurant after hearing reports of a person with a gun, police said. 

Once inside the restaurant, officers found a 43-year-old man who had been shot in the head. The man was brought to Jefferson University Hospital, where he died shortly after arriving, police said.

A family member has identified the victim as Bryan Delp.

Initial details surrounding the shooting were unclear over the weekend. But on Monday, investigators said the man was unhoused and had caused a disturbance inside the IHOP. Security was escorting the man out of the restaurant when he turned around and allegedly spat at the security guard, 39-year-old Yahaira Melendez, according to police. 

Melendez then fired a gun at the man, shooting him in the head, according to police. The security guard was later arrested and charged with murder and related offenses. 

In a statement Monday, the law firm Ross Feller Casey LLP said it was working for Delp's family. 

"We will conduct a full investigation into this tragic death. The family respectfully asks for privacy during this difficult time. We will have no further comment," the statement said. 

The local IHOP franchisee released a statement about the incident to CBS News Philadelphia. 

"The safety of our Team Members and guests is our number one priority. We take this incident extremely seriously. We are cooperating fully with the ongoing investigation. Further questions on the investigation should be directed to the Philadelphia Police Department."