Have you heard of black swans, not birds, but events? I learned of them some years back in relation to my writing. Recently because of some events, I did a search online for a succinct definition and AI provided this one:
"black swan" refers to a highly unpredictable, rare event with massive, paradigm-shifting consequences, popularized by Nassim Nicholas Taleb, who defined them by three traits: they are outliers (beyond normal expectations), have extreme impact, and are rationalized with hindsight as if they were predictable. Examples include the 2008 financial crisis or 9/11, with the name stemming from the historical European belief that all swans were white until black swans were discovered in Australia. While often negative, black swans can also be positive, like the rise of the internet, but the common usage focuses on major disruptive events.
The kidnapping of an 84 year old woman would be considered unusual in the US, but what would be the motive in this case? It is a black swan event for the family at the least, but this has impacted the country beyond the loved ones and friends. I relate to it because it's not that far from where I live, 
maybe four or five miles, and in my kind of home situation. Ours is not, of course, a million dollar home, but is in the desert terrain. The photo of her home is probably from a drone or helicopter.
There are few clues, other than some blood splatter at the front door, that police have identified as hers. Scary as well as rare. It has ended up with the FBI and other agencies besides Pima County Police. It is on the news, far and wide.
I relate to it for the location but also her age. So far, no return but some probably fake ransom notices but no proof that she's still alive. Hers is considered to be a safe neighborhood, but what is safe these days?
On YouTube, I've gotten into watching two true crime networks, A&E and 48 Hours, but try to only look where the killers have been caught and usually been found guilty. Things like this Black Swan provide no such comfort. What I have seen on those crime programs is how often illegal drugs are involved. Unlikely to be the case here. The other reasons murders are committed are within families, desire for money, hiding a secret. Ex relationships seem to sometimes end in violent results, male or female. Finally there are pedophiles and sexual predators, along with random killers, who do it for the experience...
Here is a link to one of the news investigators with more info she has gotten from a reliable source. The Suspect according to that source. Personally, I have no clue and have heard multiple theories.
Below is one of the stories that I've watched. Not connected, but an example of police work, sometimes, with cold cases, years later. Hope the one in Tucson is solved sooner and with the return of a live victim. The longer it goes on, the less likely that this Black Swan will have any kind of happy ending.