Lockable holster retention system

1. A holster for a handgun, comprising:

a cavity having an open top end, a bottom end, a frame/slide portion and a trigger guard portion, wherein said frame/slide portion of said cavity has greater depth than said trigger guard portion of said cavity;

an axis defined along a side wall of said holster, wherein said axis extends from said open top end to said bottom end;

a lever having a finger button portion and an engagement portion, wherein said lever includes a second side facing generally toward said holster cavity, and wherein said engagement portion of said lever includes a locking projection extending from said second side of said engagement portion;

wherein said lever is pivotally attached atop said side wall of said holster, along said axis, approximately between said finger button portion and said engagement portion, such that said finger button portion extends from said axis and is positioned above said frame/slide portion of said cavity and said engagement portion extends from said axis and is positioned above said trigger guard portion of said cavity;

one or more ridge segments extending from said side wall around at least a portion of said lever so as to define a recess, wherein said lever is positioned within said recess;

an aperture formed in a portion of said side wall beneath at least a portion of said finger button portion of said lever, wherein said aperture is formed within said recess; and

a lockout lever pivotably attached to said first side wall such that said lockout lever is able to be rotated between a locked position and an unlocked position, and wherein said lockout lever is positioned beneath said finger button portion of said lever when said lockout lever is in said locked position.

2. The holster of claim 1 , wherein said frame/slide portion is contoured to accept at least a portion of a frame/slide of a handgun and said trigger guard portion is contoured to accept at least a portion of a trigger guard of a handgun.

3. The holster of claim 1 , wherein said lever is pivotally attached to said side wall.

4. The holster of claim 1 , wherein said lever is pivotally attached to one or more ridge segments.

5. The holster of claim 1 , further comprising a front wall further defining said holster cavity.

6. The holster of claim 1 , further comprising a rear wall further defining said holster cavity.

7. The holster of claim 1 , wherein a first side wall is worn away from a user's body and a second side wall is worn adjacent said user's body.

8. The holster of claim 1 , wherein a first side wall is worn adjacent a user's body and a second side wall is worn away from said user's body.

9. The holster of claim 1 , wherein said holster is substantially rigid.

10. The holster of claim 1 , further including at least one means for attaching said holster to a holster holding device.

11. The holster of claim 1 , further comprising one or more slots, wherein said slots define a passive retention portion for providing frictional retention of said handgun by said passive retention portion and wherein one or more retention screws may be tightened or loosened to adjust said frictional retention between said passive retention portion and at least a portion of said handgun.

12. The holster of claim 1 , wherein said locking projection includes a ramp surface.

13. The holster of claim 1 , wherein said lever is pivotable between an engaged position and a disengaged position.

14. The holster of claim 13 , wherein said lever is biased to said engaged position.

15. The holster of claim 1 , further including a trigger guard support wall formed in said trigger guard portion to limit insertion of a handgun into said holster cavity.

16. The holster of claim 1 , wherein when said lever is in said engaged position, said locking projection protrudes into said holster cavity, via an opening in said side wall such that said locking projection extends inside said holster cavity and when said lever is in said disengaged position, said locking projection is at least partially withdrawn from said holster cavity.