Never Holster an Unloaded Pistol
If your pistol is in a holster, make sure that it is ALWAYS loaded and chambered. If it is not loaded and chambered DO NOT put it in a holster. Your failure to follow this simple rule and advisable system will almost certainly get you or someone else killed.
This means at home, at the gun range, in a firearms class, …everywhere: if your pistol is unloaded, DO NOT put it in a holster. Only holster a loaded-and-chambered pistol.