Smiley Martin, 27, was taken into custody Tuesday morning as he recovered at a hospital from injuries suffered during the gunfire that broke out in the California capital's entertainment district early Sunday morning, the Sacramento Police Department said.
Martin faces charges of possession of a firearm by a prohibited person and possession of a machine gun. Police said he will be booked at the Sacramento County Main Jail once his medical treatment is finished.
Martin is the brother of 26-year-old Dandrae Martin, who was arrested as a suspect in the mass shooting a day earlier. Dandrae Martin is facing charges of assault with a deadly weapon and unlawful possession of a firearm by a felon. Neither has been accused of homicide.
Police said that as the investigation continues, the suspects may face different or additional charges.
More than 100 shots erupted as bar patrons filled the city streets at closing time around 2 a.m. Sunday morning. Video from witnesses posted on social media showed rapid gunfire for at least 45 seconds as people screamed in terror and ran to escape the bullets.
Three women and three men were fatally shot and a dozen others were injured during the shooting.
The Sacramento County coroner identified the three women who were killed as Johntaya Alexander, 21; Melinda Davis, 57; and Yamile Martinez-Andrade, 21. The three male victims were identified as Sergio Harris, 38; Joshua Hoye-Lucchesi, 32; and Devazia Turner, 29.
Turner was a father of three daughters and one son. His mother, Penelope Scott, told The Associated Press that he was a "protector."
"My son was walking down the street and somebody started shooting, and he got shot. Why is that to happen?" Scott said. "I feel like I’ve got a hole in my heart."
Melinda Davis, 57, lived on the streets nearby and was looking for housing when she was shot.
Police said they were investigating whether a fight that broke out prior to the shooting was connected. Police also recovered one stolen handgun at the scene and were investigating whether it was used in the shooting.
Authorities have asked members of the community who have video or pictures related to the shooting to share them with investigators as the investigation continues.
Politicians have decried the shooting, and some Democrats, including President Biden, called on Congress to pass tougher gun control legislation.
"Today, America once again mourns for another community devastated by gun violence," Biden said in a statement on Sunday. "But we must do more than mourn; we must act."
Fox News' Emma Colton and The Associated Press contributed to this report.