SACRAMENTO (CBS13) — Sacramento police say they have now made one arrest in connection to Sunday’s mass shooting downtown.

On Monday, Sacramento police announced that Dandrae Martin, 26, has been arrested on charges of assault and illegal firearm possession. He is being characterized by police as a “related suspect.”

READ MORE: World's Strongest Man Competition Returns To Sacramento

Police say detectives and SWAT have served search warrants at three residences in the area as part of the shooting investigation. During those searches, police say at least one handgun was recovered.

Investigators have received over 100 photos and videos through the online portal that was set up after the shooting, police say. Detectives are now reviewing the evidence to determine charges.

READ MORE: Firefighters Responding To Growing Wildfire In Colusa County

Detectives have said they are looking for multiple possible suspects. No description of any suspects has been released.

The exact events that led up to the shooting are still under investigation, but at a press conference Sunday afternoon, police acknowledged the brawl just before the incident.

MORE NEWS: High Schooler In Roseville Had List Of Students They Wanted To Harm, Police Say

A total of six people have died in the early Sunday morning shooting that happened just as bars were getting out for the night. Twelve other people suffered varying degrees of injuries.