The reason I believe this was a random crime is because of the distance from KR's home but also because she was found in the opposite direction from her final destination. I think the killer was very familiar with the area where her car was found. KR had no reason to know the area. The crimes that happened close to your home were both personal crimes of domestic violence.
I think if KR had someone with a personal grudge--such as a former student she helped kick-out of school-- they would have abducted and killed her much closer to her home. The Creighton murders happened in nice homes in nice areas of Omaha, NE. The killer turned out to be a disgruntled doctor with a grudge against his former "teachers" who kicked him out of the Creighton's residency program. He waited years between the murders. LE did an incredibly stellar job solving it.
JMO
You could be right. It is odd she was found so far from home. But I actually feel like this just seems so personal to me, to die in such a horrible manner. We just don’t know what happened between Milwaukee and Gurnee. It is a strange case.