06/06/2011 11:28 am ET | Updated Aug 06, 2011

When It Comes to Murder, The Questions Never End

This past week, 26-year-old Raymond Clark admitted that he killed Yale University student Annie Le, 24, whose body was found stuffed behind a wall on the day she was to be married, her jaw and collar bones broken.

"I take full responsibility for my actions," he told the court, which included Annie Le's family. "I alone am responsible for the death of Annie Le, and causing tremendous pain to all who loved and cared about Annie."

He went on to say he was sorry for everything, including his own sorry life that he knew could not measure up to Annie's.

As far as statements go, it was a pretty complete exposition of guilt and remorse. But Annie Le's mother wanted more -- she wanted to know why. Why did Clark, a lab tech at Yale, snuff out the life of a beautiful soul?

"I will never see her walk down the aisle," Vivian Le told the press. "Her future is gone. I will never understand how this can happen. I miss her so much."

The Le family lawyer Joe Tacopina echoed the mother's statement: "While he certainly seemed remorseful, he didn't provide any answers."

And the truth is that, other than having their daughter back with them, what the Le family wanted most of all was to understand why Clark killed this vibrant young woman. Every murder victim's family wants to know the same thing.

Murder leaves a very black hole and it's almost like victims' families believe if they at least know why their loved one was killed, it will bring a measure of peace and understanding. It's part of being human -- we must know why.

Having covered a lot of murders in my career, I believe that many if not most murderers have no idea why they kill. Clark was driven by lust. He saw an attractive woman, wanted to have her and when she resisted, he killed her.

Does that make any sense? No. A lot of people feel lustful every day but they do not commit murder. I was speaking to a district attorney about this recently and he summed it up this way: "Murder is an irrational act. There is no way to understand it."

I believe he's right. I wrote a book called Nightmare in Napa in which a young man -- who had never before in his life received even a parking ticket -- got drunk, broke into a house on Halloween and viciously stabbed two women to death, women who were known to him. The guy pled guilty to two counts of murder and is in prison for life. The DA grilled him. Why did he do it? Why had he murdered these two young women, one of whom was his wife's best friend?

There were many theories about why, including the man's jealousy about the friendship between his wife and the woman he killed. Reportedly the dead woman wanted to break them up. So that was the reason, wasn't it? The killer could easily have said 'yes.' After all, he'd already admitted to killing two women. Why not at least admit the reason why?

Here's what the killer told the DA. He said, I can't remember why I did it. I blacked out and when I came to, they were dead.

Maybe the act of murder itself is so horrific that even those who commit it cannot fathom why.