I wondered the same thing the more I learn about this Garland. He sounds a lot like Todd Kohlhepp murderer who owned rural land and had mental issues and had business dealing issues with other people .
Once he was caught we found out about more murders the guy did.
http://www.independent.co.uk/news/w...og-south-carolina-shallow-grave-a7400651.html
I do have to wonder during Garlands other crime years where he was on the run whether he killed someone else and it made it easier for him to take out revenge on someone.
I tried looking up the circumstances of how the 14 year old died but I could not find out anything more about it other than it was some sort of accident. But the thing is he was 14 so he probably didnt have a drivers licence. And supposedly there may have been a younger girl with same last name that also died if I read things right. So wonder who was driving when they died and wonder how this Garland chap got to know about the boys particular ID.
Its not all that easy to get real fake IDs so that must have took some planning too and he was involved in lots of criminal mischief for a lot of his life. He was on the run for a number of years too.
I have a feeling more serious crimes that he was never caught for. Whether any other murders I am not sure but I would not be surprised if we eventually find out he did commit other murders in his past.