SAN FRANCISCO (KRON) -- A 12-year-old boy and several teenagers were arrested in San Francisco on suspicion of participating in a violent organized retail theft crew. Investigators said the 12-year-old boy was part of a crew that carried out at least 23 separate crimes in the city and stole more than $84,000 in merchandise from stores. "The crew ranges from ages 12-18," the San Francisco Police Department wrote on Thursday. The oldest member of the crew was 18-year-old Brandon McClain of Hayward, SFPD said. Seven more arrested members were all juveniles. Police said officers arrested a 15-year-old San Francisco boy, two 14-year-old San Francisco boys, a 15-year-old Oakland boy, a 15-year-old Oakley boy, and a 14-year-old Pittsburg boy. The 12-year-old San Francisco boy was charged with assault, robbery, burglary, grand theft, and 10 counts of organized retail theft, police said. Their names were not released because they are minors. The boys were linked to several incidents when Walgreens stores were ransacked by masked thieves who worked together as a team and followed the same modus operandi, SFPD said. On September 29, eight suspects entered Walgreens at 1333 Castro Street and stole over $15k in merchandise. The same group came back with five more accomplices two hours later and stole almost $12k in merchandise. On September 16, a Walgreens store on Potrero Avenue was targeted. "When an employee asked the suspects to stop, two of the suspects assaulted the employee, resulting in a serious head injury," SFPD wrote. Investigators believe the same crew carried out an assault on Mission Street near 24th Street on the same day. On September 9, nine suspects entered Walgreens at 2690 Mission Street. While the boys were escaping with over $1k in stolen merchandise, one brandished a gun at a security guard. On August 18, seven suspects entered Walgreens at 1333 Castro Street and began concealing merchandise. One of the thieves jumped over a counter and stole a cash register. The store lost $6,500. On July 11, seven masked boys began gathering outside a Walgreens at 2050 Irving Street. Employees recognized them and called the police, but the boys forced the door open and stole $1.3k in merchandise, police said. The case was investigated by the SFPD Burglary & Organized Retail Crime Unit, SFPD Mission Station Anti-Vendor Enforcement Unit, patrol officers, and Walgreens Asset Protection.