.22 Caliber Hi-Standard Longhorn "Double Nine"
The recent pix on Cielo Drive. com of Watson's pistol prompted me to do a bit of looking.
The left side of the gun can be seen HERE
The right side of the gun, along with pieces of the broken grip can be seen HERE
I'm guessing within the first hours (or days at least), some of the police knew the pistol was a Hi-Standard Longhorn "Double Nine". The large piece of broken grip found at the crime scene, appears to have the Hi-Standard "trigger" badge still in place. The High Standard Longhorn was a very common model and a firearms expert would probably recognize it quite quickly from the markings on the small metal disc on the piece of grip alone.
The FIRST HOMICIDE INVESTIGATION PROGRESS REPORT says in part:
"Most of the polygraph keys which could have been used were released to the press by patrol personnel prior to investigating officers' arrival on the scene, or at least without their knowledge".
Four polygraph keys that have not been released are as follows:
#2. The revolver used was a caliber 22, Hi-standard, "Double Nine" "Longhorn". The weapon has a 9 1/2-inch barrel and is 15 inches in overall length. It has a blue steel finish and a 9-shot capacity. It has walnut grips. The right grip from this weapon was broken at the scene and is in police custody. The weapon has a catalogue number of 9399."
That information may have been derived simply from the badge on the piece of broken grip, long before the rest of the gun was found.
I've included some pix of various Hi-Standard Longhorn "Double Nines", showing some of the features and markings that appear to be consistent with Watson's pistol.
The Hi-Standard Longhorn was a very common pistol with many different variations.
I read Sears had a large stake in the company and sold some models for as little as $35.
Other manufactures made similar models, it would take too long to try to contrast them here. "Hi-Standard" is clearly visible on the pic of the pistol purported to be Watson's on the Cielodrive website, other markings are consistent with those found on other examples of the Hi-Standard "Double Nine" as well.