San Diego police on Friday released video that investigators hope will help them identify a suspect in the fatal shooting of a security guard near the foot of Crystal Pier earlier this week.

Shortly after 2 a.m. Monday, several people called 911 to report gunshots, said acting homicide Lt. Christopher Leahy. Staffers at a nearby bar ran outside to find the wounded guard down. They began to administer first aid until San Diego police and paramedics arrived and took over life-saving efforts. The victim was taken to a hospital, where he died.

He has been identified as Luis Alberto Quiroz-Arreola, 31. San Diego police confirmed he was an unarmed security guard working at Crystal Pier when he was shot.

The video police released Friday appears to be security camera footage from different locations. One part of the footage shows a person dressed in dark clothing with a hood pulled up over his head, walking near the foot of the pier in Pacific Beach. Another piece shows a person riding a small two-wheeled vehicle in what looks to be an alley.

Police are trying to determine who the person is and ask that anyone who recognizes the person or who has information about the case call the homicide unit at 619-531-2293 or Crime Stoppers at 888-580-8477. Anonymous tips can also be sent through sdcrimestoppers.org.