Another few thoughts and ramblings on the belt and Peaches
The National Missing and Unidentified Persons System (NamUs)
Is it possible to date the manufacture of the belt and/or plastic tub through similar techniques in relation to radiocarbon dating(plastic maybe not)?
If the date of manufacture can be determined specifically for the tub is it possible to trace out from the manufacturer's business records to where and what places this particular make and model of plastic tub was sold? It may not in itself identify the killer but if cross referenced with other evidence it could pinpoint more details for us to analyze. My postulation in regard to Peaches in the context of 1997 is how would the killer choose Hempstead Lake State Park and Gilgo Beach areas then compared to now. This leads me to believe they're familiar with both areas and more specifically the audacity to drag a plastic tub into the Hempstead woods would suggest a fair amount of confidence that unlike in the late 2000s where one could use technology such as google maps to reconnaissance areas in 1997 anything other than first hand knowledge of such areas could possibly make the killer less assertive in choosing such a place to dump their victims. But back to the tub:
In the photos shown of the tub and contents here:
https://www.longislandpress.com/wp-content/uploads/2016/12/Peaches-696x388.jpg
What brand of tub, cloth, and plastic black bags were found?
Any marking like serial numbers or manufacturers codes/date stamps found? Is the particular floral pattern able to be traced to a known distributor/manufacturer?
What is its physical properties? Cotton? Synthetic? Silk?
What unique drag or scuff marks if any are shown on the plastic tub? Can this indicate a particular pattern that a specific make of vehicle would cause during transportation/handling?
What fibers or debris or material were found alongside the items in the photo?
As for the jewelry found is it possible to determine the metallurgy makeup and compare it against know manufacturer's values, ie 10% lead, 20% zinc, etc.?
There is also the speculation I have that I'll add among everyone else's ideas with the questions of:
1. Could the killer have been a (union based with good pay, steady income?) Parks(or similar job function) maintenance employee that had access to landscaping materials(burlap sacks) while maintaining the parks where the victims(some or all) where found(nearby or in)?
2. Shared a locker-room or similar environment where gear would need to be initialed(belt taken from fellow employee?)
3. Drove a pickup truck or similar maintenance vehicle to carry the materials and bodies?
4. Due to nature of job and interaction with other government agencies already have the first hand experience of physically where to dump victims that one could not easily get in 1997 or even early 2000s before the advent of google maps and similar technologies with such accuracy and precision?
5. Use the disguise of a legitimate Parks(or similar local government construction/town/highway dept) employee to openly and leisurely dump victims bodies without ever raising concern, being noticed and/or questioned by public/law enforcement?
6. Given the nature of the phone calls to Melissa Barthélemy sister Amanda could it be argued that the killer's calm composure, intellect and social abilities would be the product of someone who's interacted with the public and/or has a background that's customer/civil service oriented? Would this lend itself to the idea as to why some of the victims felt confident enough to see the killer and lower their guard?
Again speculation but how to rule out the possibility of this? Or rather show such conjecture to be true? Given what authorities has stated this loosely fits their description but like every other theory I have reservation.