The Glendale Police department has released photos of three people it says are persons of interest in a mass shooting on Sunday that left three people dead and five injured.

The shooting took place about 7:45 p.m. May 4 at El Camaron Gigante Mariscos & Steakhouse at 6729 N. 57th Drive in downtown Glendale.

Police officials said in a statement the three were not suspects but were people investigators wished to speak with about the shooting.

On Tuesday, police set up a portal for witnesses to submit photos and video of the event anonymously as they continued to search for suspects.

Killed in the shooting were brothers Christopher Juaquin Sproule, 21, and Damien Anthony Sproule, 17, as well as Milo Christopher Suniga, 21.

The incident escalated from a fight between at least two groups of people. There was a concert/car show taking place at the restaurant just south of downtown, police said.

Around 7:45, a fight broke out near the stage area among several individuals, who were told to exit the venue. According to police reports, onnce they exited the venue the fight escalated in the parking lot. That’s when these individuals began shooting at one another.

Those with information can call Glendale Police at 623-930-3000, call Silent Witness at 480-948-6377 or use this link to upload photos or video.