Thanks Fastbolt!
Lost Lake, the CA DOC 3913's have two letters and three number inventory numbers laser etched on the barrel, frame and slide. All I've seen start with BO then the three numbers.
If yours has no markings whatsoever, you may just have one of the overuns from that order. Yours looks to be in remarkably good condition. My TDT serial is TDT1101. Regards 18DAI