Four gang members were under arrest and a fifth was being sought in the brazen daytime killing of a 24-year-old man gunned down this month while sitting in his vehicle in East Oakland, police said Thursday.

All of the suspects in the slaying of Anthony Stevens are part of a violent street gang known as the Five Finger Mafia, officials said. Four of them were arrested on July 21 after police executed warrants around the Bay Area as part of the investigation, said Oakland police Lt. Roland Holmgren, head of the department’s homicide unit

An arrest warrant has also been issued for the fifth suspect, identified as 23-year-old Berkeley resident Tyrone Terrell Jr., who remains at large.

“Without any care, these individuals came into our community and opened fire,” Holmgren said at a news conference announcing the arrests and murder charges.

Holmgren was flanked by members of the department’s homicide unit, the Alameda County district attorney’s office and Oakland Mayor Libby Schaaf.

The killing happened July 9 around 10:30 a.m. on the 1400 block of 92nd Avenue. Stevens was sitting in his car when the five men rolled up on him and at least three opened fire, police said.

The men took off, leaving Stevens to die at the scene.

Detectives later received tips from the community leading them to Vallejo resident Anthony Wilson, 25, Berkeley residents Aoderi Samad, 23, and Derrick McFadden, 20, along with 20-year-old Kermit Tanner of Richmond.

Samad, Wilson and Tanner were all arrested in Vallejo, while police picked up McFadden in Berkeley. All four are being held in jail in Alameda County without bail.

Schaaf praised the police Thursday, calling the arrests a “critical piece in bringing closure and justice to the families that are affected by this violence.”

She added that she was “so grateful to the men and women of the Oakland Police Department who have remained laser focused in these trying times.”

Schaaf was referring to a sexual misconduct probe involving a woman in her teens that has shaken the department and prompted three chiefs to step down.

“I remain deeply sorry for recent events that have damaged community trust,” the mayor said. “But charging these four murder cases is significant. It represents our ability to solve crimes.”

Tanner is accused of driving the group to the scene, while Samad, Wilson and McFadden are suspected of shooting and killing Stevens, according to charging documents filed by the Alameda County district attorney’s office.

All four men were charged with murder. Prosecutors slapped Wilson, Samad and McFadden with enhancements of intentionally discharging a firearm, causing great bodily injury.

Two of the suspects are known Bay Area criminals. Wilson was convicted of second-degree robbery in Alameda County in 2010 and Samad was convicted of second-degree commercial burglary in San Francisco in 2012.

What’s more, Samad was convicted a year later of unlawful firearm activity in Alameda County, prosecutors said.

The Five Finger Mafia is an infamous Berkeley street gang that also operates in North Oakland and West Oakland and is known for street robberies, Holmgren said.

Evan Sernoffsky is a San Francisco Chronicle staff writer. Email: esernoffsky@sfchronicle.com Twitter: @EvanSernoffsky