What's with that creepy stare?

Something has been bothering me about the recent spree killings, other than the sheer horror of the events themselves.

Look at news photos of Adam Lanza who murdered 27 people in Newtown, Conn., 20 of them little children.

In more than one picture of Lanza there's this wide-eyed stare that's really creepy. Even in one of him as a child with a big smile on his face, there's this unnerving blankness in his wide-open eyes.

Look at pictures of James Holmes, who fired on people in a theater showing "The Dark Knight Rises" in the Denver suburb of Aurora last July, killing 12 people and injuring 70

In many pictures of Holmes there's that same creepy wide-eyed stare.

Jared Lee Loughner gunned down 19 people, including a little girl, and seriously wounded Rep. Gabrielle Giffords among others, in Tuscon, Ariz. in January 2011.

Same wide-eyed stare. And there is a photo that purports to be Loughner as a high school student when he had lots of hair, but at least a hint of that stare.

Now if you follow someone around take a lot of pictures of them you're going to get some with odd expressions on their face: mouth wide open, maybe a yawn, a facial tic, whatever. Some seem more prone to certain expressions than most. Both Hillary Clinton and Cheri Blair (wife of former UK Prime Minister Tony Blair) often seem to get caught with that weird wide-eyed look.

But that's a few photos out of thousands. Unless the media are culling the photos that look most menacing, these three spree killers seem to have that look on every time a camera pointed at them.

Is it crazy? Is it drugs?

It certainly looks like drugs, and some reports have claimed most or all recent spree killers have been on some kine of psychoactive medication. Some were known to be illegal drug abusers.

So the question remains, were they on drugs because they were crazy, or were they crazy because they were on drugs? Or some combination of both, such as having a bad reaction to a prescribed anti-psychotic drug?