A holster for accommodating a handgun having an attached, offset accessory, including walls defining a cavity for receiving the handgun and the attached accessory, a retention means that is capable of retaining a handgun and accessory in the holster, wherein the retention means includes a lever that is pivotally connected, via a pivot pin, to the first side wall approximately between a finger button end and an engagement end, wherein the engagement end includes a locking portion, formed on a second side of the engagement end, wherein the lever is pivotable between an engaged position and a disengaged position and wherein the lever is biased, via a spring means, to the engaged position, such that when the lever is in the engaged position, the locking portion may extend inside the cavity and inside the inner surface of the trigger guard of a handgun that is secured into the holster.