I've seen a few videos on YouTube about the case. One of them while definitely listing off potential suspects also noted that there were actually similar murders of a couple of other people back in the day, & even suggested that it could have been a random stranger that did it (not realizing its victim happened to be a celebrity), & was in fact tied to those other murders as well.
I can't remember which video it was, but, if I ever find it again, will share it on this thread.
Well the movie based on him strongly implies it may have been John Carpenter... Tho he was never charged. He was acquitted. Another theory is that his Wife Patty did it for money. But due to time and more DNA testing it's yielded no conclusive results.