Detectives received a telegram from the Midwest manufacturer of the Winchester brand bullets stating "Super X Lot TL21: Quantity packed: 40,960 boxes of 50s (bullets per box). No idea where shipped". However, Sheriff Webster did find this manufacturer's lot number was sold at the base exchange of the Vandenberg Air Force Base, 30 miles (by crow) northwest of the crime scene. If each ammunition box contained 50 bullets, the four boxes at the crime scene once contained 200 bullets. If three were partly filled (let's say 50% filled), there could have been approximately 75 bullets in boxes 1, 2 and 3 (and some in box 4 before being used).
If these bullets were the ones used by the killer of Robert Domingos and Linda Edwards, then this practically negates the idea of a murderer that was known to the victims, who trailed them to the crime scene with prior knowledge of their movements that day. The idea that such a person (or persons) would lump around four boxes of ammunition to Canada Del Molino, place them inside the shack, murder the young couple using but a fraction of this ammo, then depart the crime scene in absence of three partly filled boxes of bullets they never had to bring to the crime scene in the first place, is quite ludicrous. Everything points to a killer who was either in the shack just before the arrival of Domingos & Edwards, or a person who kept his ammo in the shack and was traversing the coastline at the point they arrived at the beach. He could have encountered the couple while returning to the shack.
If the murder of Robert Domingos and Linda Edwards was a spontaneous act of rage following a conflict between Robert and the killer as explored in a previous article, and not a long premeditated act by somebody who bought the ammunition for the purpose of murder, then the Vandenberg Air Force Base as the point of purchase for this ammunition, could be more important to this case. If the murderer wasn't a wandering transient but somebody who lived at a fixed address, it is likely he would use the "least effort principle". He may want to buy ammunition in bulk to save money, however, he wouldn't likely travel a great distance from his home to achieve this. Most people (pre-internet) would shop locally within reason. If our killer bought this ammunition with the express intention of murdering somebody with it, then he wasn't likely to purchase it from an establishment close to his home and risk the possibility of it being traced.
On the other hand, ammunition purchased without malice aforethought isn't likely to require any caution. So if our killer bought the ammunition at the Vandenberg Air Force Base, it is possible he either worked there or lived nearby, such as Lompoc or Mission Hills..One investigative avenue employed by detectives was to search for transients known to use the shack, as well as locating and interviewing individuals who frequented Canada Del Molino in the days, weeks or months prior to June 4th 1963, who may have crossed paths with somebody in possession of weaponry and a regular visitor to this stretch of coastline (who stopped visiting the area after the murders). If they knew such an individual, who also worked or lived in the region highlighted below, then that would be as good a place as any to start.
Six in depth articles examining the murders of Robert Domingos and Linda Edwards.
The Ballistics. The Shack. The Rope. The Beach. Pistol or Rifle? The Final Analysis.