My Columbo binge continues and I've noticed something else -- most of his killers do make mistakes. The conductor (one of my favorites) retrieves his boutonniere from beneath the piano of his victim; it's the lack of a boutonniere in the televised concert that proves to be his undoing. Jack Cassidy, as the vengeful publisher, sets up an alibi that includes being on a drunken spree and professes to remember little of his evening, yet immediately knows that the parked car he hit contained more than one person. Given that Columbo always catches his killers, it's hard to argue that any of the crimes can be considered perfect, but I'll be curious to see if anyone executes flawlessly -- that is, according to the plan he/she laid out -- and still gets caught.

Besides, "perfect" crimes are rare and possibly accidents, relying more on the silence and discretion of the killer than anything else.

Seventeen years ago in Baltimore, a woman disappeared. Her name was Susan Harrison and the last person to see her alive was her estranged second husband. (Unless, of course, someone else killed her, in which case that was the last person to see her alive.) She visited her second husband's home on the eve of a trip she was to make with her youngest son. (Both her children were from her first marriage.) She never came back.

Susan and Jim Harrison had a violent relationship. Her older son once took photographs documenting the results of a beating. I suppose I should be saying alleged this and alleged that, but Jim Harrison is dead, too, now. Mourned, I assumed, by his own family. And, again, it should be noted that he was never charged criminally with Susan Harrison's murder.

I wrote about the case in 1995. I interviewed Jim in the basement of his home, an expensive suburban house that had been allowed to go somewhat to seed. Baltimore County police asked me not to go alone. I kept an open mind about the case. My job as a journalist was not to solve it, but to examine how everyone believed Susan was dead -- except for Jim. Only he talked about how she might turn up again.

Her body was found in '96. Her sons brought a civil suit against her husband. I believe it was settled. At any rate, I don't think the terms of the resolution were ever made public.

But if Jim Harrison did kill Susan Harrison, he committed a perfect crime. And given his history as a drinker -- let's just say it's doubtful that it was something conceived in advance.

Again, we are now dealing with a hypothetical. If one believes that Jim Harrison killed Susan Harrison, then it happened something like this:

1) Susan Harrison is killed on Jim Harrison's property late Friday, early Saturday in August 1994.
2) Jim dumps the body in a wooded area where it would be found two years later. (It was determined then that she died from blunt force trauma.)
3) There is the matter of her car, a green Mercedes, which will be found in a lot at National Airport. According to the theory, Jim drives the car there, takes the Washington Metro to Union Station, takes an Amtrak train to Baltimore, then the Light Rail to his home, which is within walking distances. He pays cash for all transactions.
4) Later, asked where he was on that Saturday, he says he took the Light Rail to downtown and Baltimore to walk around because it was such a beautiful day. It was, warm but dry, atypical weather in a Baltimore summer.

Again, this was the working theory, advanced by Susan's family. If it happened this way, the plan was concocted fairly quickly and executed flawlessly by a man who, more likely than not, wasn't completely sober at the time.

The Baltimore detective who worked the case told me he once took Jim Harrison to a Mass for missing people believed to be crime victims. In the middle of the Mass, Harrison got up and worked his way to the front. Was it possible that he might confess?

No, he gave a speech about how much he missed Susan.

I had just found an agent for my first crime novel about the time I started work on this story. I said I would never use it as the basis of a novel. The family gave too much of themselves. It is one thing for me to fill in the gaps of stories that I've simply read in the newspaper, like everyone else. But to write a novel based on a real-life event in which so many people shared so much -- I can't do that.

But one day, I might write a novel about someone who committed the perfect crime almost by accident. And, I hope, deconstruct the oxymoron that is "perfect crime."