The Contra Costa County Sheriff’s Office today announced additional arrests in connection with the theft of weapons from the sheriff’s office and California Highway Patrol late last year and early this year.The arrests and recovery of weapons were the result of a joint investigation by the sheriff’s office and the FBI. In April, Sheriff Warren Rupf said Daniel Vess, a 20-year-old Montalvin Manor man, was arrested in connection with the thefts after investigators served search warrants at his home and allegedly found a stolen assault rifle and other modified weapons. Officers also recovered ammunition, ballistic vests and helmets from the home, according to the sheriff’s office.Today, the sheriff’s office said 22-year-old Brandon Buchanan of Stockton was arrested after investigators served a search warrant at his home on Thursday. The stolen weapons were sold to a person who allegedly later sold them to Buchanan, the sheriff’s office said. Additionally, Kao Saephan was arrested May 28 in connection with the case for allegedly possessing a stolen weapon, according to the sheriff’s office.”We are extremely pleased our joint effort resulted in these arrests and the recovery of the missing weapons,” FBI Special Agent in Charge Stephanie Douglas said in a prepared statement. “It is imperative we pursue those who facilitate a violent crime.”Buchanan, who faces federal charges, is being held at the Martinez Detention Facility for possession of stolen property, possession of an assault weapon and altering the identification of a firearm, the sheriff’s office said. His bail was set at $360,000.Vess is in federal custody, according to the sheriff’s office.The first burglary happened in mid-December at the CHP office at 5001 Blum Road in Martinez. A burglar cut a fence surrounding a secure lot, crept past motion-sensor lights and stole a tactical rifle and ammunition out of a patrol car, CHP Officer Tom Maguire said shortly after the incident.Then on Jan. 5, three AR-15 assault rifles and a shotgun were stolen from vehicles parked at the sheriff’s Field Operations Building in Martinez. A vehicle was also broken into at the sheriff’s Bay Station in Richmond, according to the sheriff’s office.Another break-in happened Feb. 25 at the sheriff’s shooting range near Marsh Creek Road in unincorporated Contra Costa County.The sheriff’s office said all the stolen weapons have either been recovered or are believed to be accounted for. One AR-15 was not located, but the sheriff’s office said it may have been disassembled for parts.