What do you look for when tracking for serial killers?

[Dylansmom08]

I wasn't sure where to post this but I have been looking at the unidentfied Jane Does to see if any of them could possibly be connected in some way. I found something that seems rather strange and just sticks out to me maybe a possible serial killer could be to blame but I'm not sure what criteria have to be met for them to be labeled serial killer victims. Here is what I found if anyone wants to give some input that would be great.
I have come across a pattern of women all found on the interstates or nearby along major highways leading to the interstates. All of these women are of mixed race and in the same age range. One was even found in a patch of woods directly behind a Distribution Company by a truck driver.
Here are the links for the ones I have found so far
The National Missing and Unidentified Persons System (NamUs)
Body of unidentified teen or young woman found in Clear Creek County, composite sketch released – The Denver Post
The National Missing and Unidentified Persons System (NamUs)
The National Missing and Unidentified Persons System (NamUs)
The National Missing and Unidentified Persons System (NamUs)

 

[Kell1]

There are some 500 unsolved murders attributed to long haul truckers that are the basis of the FBI's Highway serial killing initiative.

It wouldn't be a shock to anyone if these were part of that study and on going investigation