them in court cases. The unit averages 45 arrests yearly. Tactics Since its initial formation, the SIS has developed a reputation for their tactics, considered unconventional in law enforcement. The SIS can surveil suspects for lengthy periods of time, reportedly for weeks on end, with some stakeouts continuing well after the suspects leave the LAPD's jurisdiction or even California. Many of the SIS's stakeouts do not result in arrests, and detectives typically move on to other suspects when it is apparent that a suspect may not actually be a criminal. Though the SIS typically surveils burglars and robbers, they also surveil murderers, kidnappers, rapists, sex offenders, and corrupt police officers. To provide undoubted proof of a suspect's guilt, the SIS surveils suspects as they commit a crime—"standing by" as the crime is committed—then moves to apprehend them when they attempt to leave the scene. Though controversial and criticized for potentially putting people at risk, no civilians or bystanders are known to have been killed by a suspect being surveilled by the SIS. The LAPD states this is effective at stopping "streetwise, career criminals"—as it is easier to prove wrongdoing in such cases as opposed to arrests for conspiracy or attempt, and intervening could potentially escalate the situation into a standoff—viewing it as protecting more innocents in the long term. Following a 1988 Los Angeles Times exposé on the SIS's methods, the unit began to shift their tactics to intervene in crimes or arrest suspects before crimes are committed "whenever practical". During arrests, SIS detectives typically wait for suspects to attempt to leave in a vehicle. They then surround the suspect vehicle with their own vehicles and block it in to immobilize it and ensure suspects cannot exit their vehicle or drive away, a tactic referred to as "the jam". Most of the SIS's shootings occur while the unit is "jamming", but the LAPD states it allows the detectives to choose when and where suspects are arrested, thus minimizing the risk to bystanders. Reportedly, the SIS does not inform other police units of their operations beforehand. The SIS is known to train special forces, namely Delta Force and U.S. Navy SEALs, in surveillance methods. Equipment During their operations, the SIS wears plainclothes and drives civilian undercover cars. They are issued bulletproof vests, which they only equip shortly before an arrest. The SIS is authorized to carry "any weapon in any caliber