Thank you, I'm happy to help.

There are a number of good publications I can recommend, Doctor Christopher Berry-Dee's publications "Talking With Serial Killers" and "Talking with Psychopaths and Savages" are pretty impressive and comprehensive.

If that's to much hassle, I found a few interesting links with a quick search:

https://www.fbi.gov/stats-services/publications/serial-murder

http://crimeslab.com/different-types-serial-killers/

https://www.psychologytoday.com/us/basics/serial-killers

https://sites.google.com/site/psychologyofpsychopaths4a/what-is-the-profile-of-a-serial-killer-1/what-are-the-different-types-of-serial-killers

https://www.psychologytoday.com/us/blog/wicked-deeds/201909/understanding-what-drives-serial-killers

I hope some of these prove helpful.