minimize the difference caused by the different trigger pressure between the first double-action shot and subsequent single-action shots when the hammer is cocked by the rearward movement of the slide. SIG Sauer refers to their safety systems as a Four Point System. The four types of safety are: the de-cocker, which allows the shooter to lower the hammer safely, while there is a round in the chamber. When the de-cocking occurs, the hammer is lowered but it still stays away from the firing pin. the safety notch, prevents the hammer from striking the firing pin accidentally. the firing pin has its own safety, which makes sure that the pin will not move forward. That is, until the trigger is pulled, at which time the safety is removed and the pin is pushed forward to meet the cartridge's primer. This third safety is also the gun's drop safety. Even when dropped from a reasonable height, with a round in the chamber, the gun will not fire. the slide has a notch, which separates the firing pin from the cartridge. Unlike the aforementioned firing pin safety, this one is there to make sure that the gun does not accidentally discharge a round while it is cycling. This is called the "trigger bar disconnector". Despite these safety measures, the Sig Sauer P220 has been cited in accidental fatalities. One example is the case of Officer Jesse Paderez of the San Fernando Police Department, California. On 17 July 2002, he was "accidentally shot and killed when his Sig P-220, .45 caliber service weapon, fell to the ground and discharged, striking him in the head. He had gone to the police station to pickup a patrol car...as he walked across the parking lot, his weapon, still in its holster, fell to the ground and discharged when the hammer struck the pavement." Variants The original 1975 SIG Sauer P220 had a 'heel-mounted' magazine release lever located at the rear of the magazine well and a lanyard loop which was typical of handguns made for police and military purposes. Newer SIG P220s utilize a push button magazine release to the left side of the grip, behind the trigger and do not have lanyard loops. The P220 was then later modified with a redesigned slide, grips, and other minor changes to the frame. In 2007, a Picatinny rail was added to the frame under the barrel as standard