100% killer was familiar with area and preplanned murder. Possibly a local to the Avon/Caledonia area and likely had a travelling job with odd hours. Given the promotional Jacket from the Watkins Glen, I'd suspect his job probably pertained to something like an Automotive Sales Rep.Welcome to WS.
I take an interest in this case for the simple fact the murder happened close to where I live, as well as the fact it's unsolved.
There's a possibility here that the victim was with this perpetrator for a decent amount of time, say many hours or perhaps longer. Which I think maybe explains the close up and personal demise of this poor young woman. He had to be situated within a very short distance to her to shoot her in the manner described by law enforcement.
I believe the perpetrator knew he could carry out such an act because this young, vulnerable teenager needed him, and might trust him. He also would have known about her background, no doubt she told him during the car ride or perhaps at the diner. So we have a situation where the worst of humanity figured he most likely could get away with her murder.
Location:
The location of the diner where they ate, and the general area where he committed the crimes, I think was already known to the killer. The nearest, finished interstate highway during that time is a short drive north of there. He also had to have known U.S. 20 along there.
Interstate 390 was completed through there in 1982. U.S. 15 was the main north/south route through there, for many years. I maintain the killer knew that area well. I think he would have had to have known it well, in order to make a quick escape. The roads are generally not very straight. It's also very hilly due to glacial activity. Not many clear lines of sight over long distances. This happened in the evening hours.
My hunch is this was someone traveling a fair distance. Witnesses described a young man. One could surmise he was single, and no one was expecting him home during that period of the day. So most likely living alone.
He could have called ahead and told a family member he was delayed and decided to spend the night at a local motel. There were plenty of these motels located along both U.S. 20 and U.S. 15 back in those days, also near interchanges along the N.Y. State Thruway (I-90).
I agree @ZohanJB , it's most likely this was premeditated. The killer planned this ahead of time.
I would be inclined to look at similar cases around the same period of time, in nearby U.S. states.
In post #536 above, the documentary claims truckers saw Tammy Jo at a nearby truck stop. Most likely this was along I-90, but I will say "nearby" may be a relative term in this case. That could be Buffalo. There would have been maybe 2 or 3 along I-90 south and west of Rochester.
JMO
A traveling automotive sales rep based in this region could plausibly:
-Know the Route 20 area well
-Be comfortable committing a crime in a rural field
-Have access to promotional racing jackets (e.g., Watkins Glen)
-Travel far enough to encounter Tammy without local ties being obvious
Not to discount other potentials, like a trucker, but the access to the jacket implies a level of car enthusiasm that transcends the average person. and given that the killer was comfortable leaving the jacket with the victim suggests that he may have thought police would link the jacket to those that purchased it at a promotional event. I assume if he was a rep and had access to the jacket, he likely had multiple which may be why Tammy felt comfortable taking it.
Now this is speculative of course but there are some aspects of the profile for this killer that must be true or at least highly likely.
1. The murder was not spontaneous. He chose that location deliberately and that time deliberately.
-Traffic on Route 20 is virtually zero
-Patrol activity is minimal
-The offender has absolute control of time and setting
He knows:
-Where headlights show on the horizon
-Where no houses have line-of-sight
-Which pull-offs aren’t monitored
2.He was familiar with the location. You don’t commit an on-site homicide in a pitch-dark field unless you’ve driven past it repeatedly.
3. The timeline matches someone routinely on the road late
Sales reps, truckers, and regional drivers often traveled late into the night in the 1970s.
4. The killer likely had "functional territory" overlapping Avon/Caledonia area
This could be:
-A sales territory
-A trucking route
-A delivery path
-A habitual recreational drive
-A commuting route between counties
5. The Jacket
-A person attending Watkins Glen events or receiving promotional materials could easily have possessed a jacket like Tammy's.
Now as far as the timeline goes:
*=my opinion
Evening (8:00 pm – 11:00 pm)
Offender is traveling Route 20 or nearby highways after finishing:
A late-day sales route*
Driving home from a regional job
Returning from a trip
Or simply passing through the area en route between Rochester, Buffalo, or the Finger Lakes
At this time:
Traffic is thin
Hitchhikers (like Tammy) are more visible
The offender might stop at:
Gas stations
24-hour diners*
Truck stops
Bars
Small-town intersections
It’s during this window that Tammy was most likely picked up.
Late Night (Midnight – 2:00 am)
Tammy is in the offender’s vehicle.
Key behaviors during this phase:
He takes a familiar-long route*
stops for food (matching stomach contents)
Heads southwest, west, or north depending on his route pattern
By now, he has:
Assessed her vulnerability
Developed a false sense of rapport or control
Moved her progressively toward an isolated area
An offender who routinely travels Route 20 would know exactly where the darkest, least traveled sections were.
Early Morning (2:00 – 5:00 am)
This is the highest behavioral-likelihood window of the murder:
Traffic on Route 20 is virtually zero
Patrol activity is minimal
The offender has absolute control of time and setting
He turns off onto the field access area near Caledonia/Avon that he is already familiar with.*
He kills Tammy on-site — a sign of confidence in that specific location, not improvisation.
What the timeline suggests...familiarity
-He drove route 20 often
-he understands rural police rhythms
-he's comfortable navigating rural roads in the dark
-he likely had a reason to be out late
Ultimately,
The timeline and geographic logic strongly support an offender who was a repeat traveler on Route 20, with predictable familiarity with rural Livingston County, but not necessarily a local. Although, I do suspect this area was familiar and comfortable enough to the killer that they likely were in the radius of where they lived.
Someone mobile, car-oriented, and often out late — like a traveling automotive rep.