The First Forty-Eight Hours

I've begun a series based on the book Murder one: A Writer's Guide to Homicide by Mauro V. Corvasce and Joseph R. Paglino. In my last post, I offered the definitions of five types of murder. Today I want to focus on the first 48 hours. 

All homicide investigations follow a fairly basic procedure, and I'll discuss those procedures in my next posts. First, I want to discuss the timeline for an investigation. Most solved homicides get that way within the first forty-eight hours. After that, it becomes exponentially harder to solve--not impossible, just difficult. There are several reasons (copied directly out of the book):

1. Eyewitnesses who have not stepped forward probably will not appear. And their memories of the event, of course, become less clear.

2. New clues at the scene of the crime probably will not surface after the initial investigation and analysis have been completed.

3. If the murderer has left a trail of clues or if the police know where the killer is hiding, an arrest has been made or is imminent.

Because the first forty-eight hours are so critical, most detectives work around the clock to gather evidence, follow up leads, and conduct interviews. Keep that in mind for your book--no clocking out at five o'clock during that first forty-eight. Also keep in mind that new information is much harder to find after the first two days, so if  you're going to dole out clues at a more leisurely pace, make sure it's believable. For instance, ballistics reports take longer than the two-day window, so if solving the crime depends on a ballistics report, that would be believable. Check with the crime lab in the area your book takes place and ask how long the wait is for standard tests like ballistics, DNA, trace evidence, and things of that nature. You'd be surprised at the amount of time it takes for these. It's not instantaneous like it is on the TV show CSI. 

Lastly, most homicides are committed by someone who knew the victim. Because of this, investigators focus most of their attention on the victim's immediate family, friends, co-workers, and neighbors. Investigators are looking for means (they had the physical strength to do it and had access to the murder weapon), motive (a reason for killing the victim, even if it was accidental like the victim being caught in a drive-by shooting), and opportunity (they were with the victim at the time of the homicide - no alibi). Those rare instances where the killer did not know the victim are difficult to solve because the suspect list isn't as limited as friends/family/co-workers.

In my next post, I'll begin discussing the six steps investigators use to solve a homicide.

-Sonja