In two newspaper reports, the "hitchhiker" is described as notifying an East Nicolaus Highway Patrol officer of, what he described as an accident. There are further newspaper reports stating that the "hitchhiker" informed authorities in Marysville, Yuba County. However, we are led to believe this "hitchhiker" was never traced. These two accounts of a "hitchhiker" reporting the couple dead in their vehicle to an East Nicolaus officer and to authorities in Marysville, California, appears to suggest that this person was just a concerned citizen traveling from, or through Sacramento to Marysville on a direct route from south to north. The notion of a nefarious criminal (or Zodiac Killer) twice playing games with officialdom, appears the less likely narrative regarding the murders of Koy Ien Saechao and Choy Fow Saelee.
The distance between the crime scene and East Nicolaus is approximately 22 miles. Had the "hitchhiker" continued north to Marysville Police Department, this would have been a further 15 miles. It appears that this person was just a helpful citizen, notifying authorities of his tragic discovery, rather than a Zodiac Killer playing "cat and mouse" games with the police. However, the newspaper reports may have been the inspiration behind the author of the May 6th 1986 "Zodiac" letter, claiming "The Blue Meannies almost caught me". This may exempt the "hitchhiker" being responsible for the crime, but doesn't necessarily preclude the Zodiac Killer being the orchestrator behind the double murder of the Laotian couple.
We have to weigh up the probability of the couple opting to take a rest by the side of Highway 99 just 40 minutes from home, with the likelihood they were flagged down by a trailing motorist, akin to the ruse supposedly orchestrated on Kathleen Johns near Modesto in 1970. This, allied to the style of the attack at Blue Rock Springs Park on July 4th 1969, is enough to pause for thought. Exactly two weeks after their murders, a letter arrived at the San Francisco Chronicle offices on May 6th 1986 claiming responsibilty for the crime, stating "I want you to know about my latest slaves I collected about two weeks ago up by Sacramento. They were killed by a freeway".
This letter has been unequivocally linked to the author of the October 28th 1987 letter, which has been equally linked to the July 31st 1969 Vallejo Times-Herald letter, detailing the murders at Blue Rock Springs Park and Lake Herman Road in Vallejo and Benicia respectively. This indicates that the origin of the 1986 "Freeway" letter lies squarely at the hands of the Zodiac Killer. Whether he was the actual murderer of Koy Ien Saechao and Choy Fow Saelee is an entirely different matter. But the crime itself, bearing in mind the limited publicity it received, appeared rather a fortuitous discovery by the Zodiac Killer had he not been present on Highway 99 in the early morning hours of April 22nd 1986.