While researching my mysteries, I’ve tracked, ridden alongside of, and eaten meals with homicide detectives, and every one of them has been smart.
Their sensibilities differ from my own, though. As a writer I spend as much time in the minds of killers as the minds of detectives, and I try to love all of my characters: detectives, killers, and victims alike. Partly to get through the day, I suppose, the homicide detectives I’ve met see less moral and emotional ambiguity than I do.
To them, killers are scumbags, no exceptions. And, to them, many victims also are scumbags, though in their case exceptions occur for those the detectives describe as innocent: the rare individuals who die without having been out on the street gangbanging or selling drugs or pimping or whoring. Who are the good guys? The detectives themselves. At least some of them. They might have doubts about the guy in the next cubicle.
While I think that these detectives miss a great deal of human complexity, I never would want to sit in a small room behind a locked door with them, trying to convince them that I was innocent if they knew I was guilty. They’re very good at what they do.
I’ve asked how they interrogate a suspect, and they’ve replied only vaguely. But, as far as I can tell, they do consistently raise a number of questions in one way or another, sooner or later. Many of the questions are obvious, but that makes them no less valuable. What follows is a short list of them. The last – in my opinion – is the most important.
Detectives ask for the story, and after the suspect tells it, ask him to tell it again. And then again. They listen for inconsistencies and for over-consistency. Some detectives ask suspects to tell their stories in reverse order.
(2) Where were you when it happened?
In other words, what’s the suspect’s alibi? Or, if the suspect was present but claims to be innocent of a killing, where was he in relation to the crime?
(3) What do you make of this?
If detectives can present the suspect with physical or circumstantial evidence, the suspect is (in the official jargon) screwed.
Put a couple of guys together and let them think that no one’s listening. They’ll start by talking about sex or the hot new detective with the tattoo on her wrist, and then they’ll talk about their latest murders. At least sometimes.
Comfort and discomfort a suspect. Play good cop and bad cop. Ever since Miranda v.
Studies have shown that we’re more likely to talk to people who look and sound like us.
Detectives bluff. They lie. They might tell a suspect that a neighbor saw him leaving a victim’s house, or that his friend has betrayed him, or that forensics has found his fingerprints even though he was wearing gloves. In most cases, cops can lie legally during an investigation.
Questions like these probably will get no new information, but they might open paths for other questions.