Serpa holsters are Blackhawk's line of weapon retention holsters. Given that just about everything Blackhawk makes has a name for an acronym, the automatic assumption would be that Serpa is an acronym as well. It actually isn't - it's named after Michael Serpa, who developed the retention system used in this holster design.
A data point which will become very important later in this story, is that police officers are generally either uniformed or plainclothes. Uniformed officers typically carry their weapons in retention holsters, and non-uniformed officers (detectives, plainclothes officers, etc) typically don't. This can present some major re-training issues when a detective switches over to a uniformed role in a department. Another issue is that retention holsters with non-instinctive release mechanisms present further training issues. When recruits first leave the academy, typically they're very good at drawing their weapons from their retention holsters. However, six months later when they re-qualify, half of them would end up tugging their gun belts up around their armpits as they attempt to draw their weapons, due to lack of practice with releasing the retention system. Given the relatively mild stress of a timed test, it's scary to imagine how someone with this problem would react under fire.
What Precipitated the Serpa Holster Design
After seeing a news story about a police officer's death, Michael Serpa decided that police needed a retention holster system that operates naturally with the method by which officers are trained to draw their weapons. At the time, detectives were typically not issued retention holsters, and had only simple holsters. The detective had been killed because a suspect drew his weapon and used it on him. Although Mr. Serpa wasn't a 'gun guy' or shooter, he did realize that a retention holster's release mechanism should operate automatically, releasing a gun when an officer draws it the same way he normally draws one that isn't holstered. In short, the retention system should be invisible. Serpa's subsequent invention was the paddle release mechanism which came to be used in the Serpa level 2 holsters.
Drawing Naturally with the Serpa
For the last several years, military and police have been training folks to draw by wrapping your fingers around the handle, pinching the gun with the thumb and index finger, and lifting it from the holster. The index finger should rest on the weapon's frame, above the trigger well for safety. This is to prevent folks from inadvertently pulling the trigger when drawing their weapon. It may be funny when Barney discharges his revolver while drawing on the Andy Griffith Show, but it's not funny in real life.
Upgrading the Serpa Platform to Level 3 Retention
Some police departments mandate the use of level 3 locking holsters, as opposed to level 2. My understanding is that Michael Serpa was not involved in the design of the level 3 retention system.
Testing Methodologies for the Serpa Holsters
The Serpa holsters, made from the synthetic above, are frequently set up in various 'torture tests' at trade shows to show them off. Tests have included securing them to a door frame and inviting folks to do pull-ups on them, etc. However, the in-house testing of retention holsters at Blackhawk once involved actual wear (and a bit of tear, on the testing folks at least). A 6'3" 280lb ex-wrestler with judo experience would walk down the halls at the office with a holster and an aluminum dummy gun, looking for someone to strap the holster to and then try to get the gun from. The subjects would typically end up getting thrown into cabinets, up against walls, etc and wind up with some fairly substantial bruises. Although they may have an office full of ex-military and ex-law-enforcement folks, folks finally got tired of this and insisted that the tester find another way to test the product.
A solution was found: attach the holster to a belt, and put the belt around a telephone pole out in the parking lot. The tester would then proceed to try to rip the gun out of the holster. Any holster design which failed, would get redesigned. This became known as the "telephone pole test".
Composition of the Serpa
In typical Serpa holsters, 5 different synthetic materials are used. The concealment holsters, for example, use Blackhawk's proprietary carbon fiber blend for the body, belt loop, and locking lugs. Other synthetics may be used for the paddle, certain bushings, etc. In the drop leg holster platform, for instance, Blackhawk uses Santopreme, which is a more flexible and rubber-like material, thus far more comfortable when worn on the leg. Metal parts are also chosen for appropriate flexibility and composition, which means that on one holster design you may find brass, blackened stainless steel, and stainless steel parts.
Related Points of Interest
See GearSerpaL3Sig for photos and an in-depth analysis of the Serpa level 3 retention system, as used with a Sig 229 pistol.
See RefBlackhawk for overall information on Blackhawk itself.