I've been reading a book, Crime of the Century, about the 1966 mass murder of 8 student nurses in a Chicago townhouse by a man named Richard Speck. While of course there are many differences between the Chicago case and the deaths of these 4 kids from Idaho, looking at older cases helps me with thinking about the range of possibilities, from motives to how a killer manages to control and murder 8 people to why the prosecution or the judge or the defense makes certain choices.
It's striking that the 1966 went to court much faster and the trial itself didn't even take 2 weeks. I have no evidence to back up this point, but modern forensics can make identifying and processing evidence before trial seems to make trials take longer. There's DNA and blood spatter and hairs and fibers and shoe prints, on and on. In high profile cases, defense attorneys want to put as much time between the crime and the trial as they can; witnesses forget things, they move away, they change their story, they lie, they're intimidated by someone. And they make motion after motion to create potential issues for appeal.
In the 1966 case, there was no issue about a jury visit to the crime scene, where 8 victims had been stabbed and strangled. The prosecution used a dollhouse size model that became a sensational visual aid when the lone survivor testified. They also brought in a door from the town house that had 2 of Speck's fingerprints. Today, the 3-D type models would be much more helpful in helping the jury visualize the scene as it was or to illustrate the prosecution theory of the case.
Finally, regarding tearing down the house: the last part of the book talked about how years later (when the book came out) the surviving victim, the families, the students who lived in the adjacent townhouse, the police officers and the prosecutors never really "healed" in some ways. The nurse who survived said 50 years later, that she still had nightmares. In an interview, one family member said, "I'm still devastated. One year or twenty it's all the same. My mother...was totally destroyed." Years later, a classmate said, "I was afraid to sleep alone, to drive or to go out at night."
I point this out to say that it's impossible to overestimate the trauma that the family members (probably going into the next generation) are experiencing. But there are many others who experienced trauma as a result of this monstrous murder. (I mean "monstrous" in also its etymological root, meaning to "warn.") The student nurses in that class and that school were forever changed by the killings, which "warned" them that people like Speck exist. The boyfriends, the fiancés, their teachers, hospital personnel, first responders all lived with what happened or what they saw in that house for life.
It was the right thing to do to tear down the King Rd. house once it was clear that there is no more evidence to come from that place. And it will be the right thing to put up a memorial, wherever that goes. There's a needed balance between (1) turning a murder house into a tourist attraction for ghouls and a constant trigger for those who are already traumatized and (2) forgetting what happened to the victims there. It's best for the students on the campus, for the neighbors, for the community and the university. It's best for some of the families, too.