Crime Scene Response: The Walk-thru

In the last installment I wrote about the call out procedure for the criminalist. Once the CSI arrives on scene though, then what? I’m glad you asked! We begin by finding the first responder(s) on scene. This is usually an officer or deputy but sometimes a detective may be there already too. Before we break out the slide rulers, lasers, and whatchamacallits we have to find out what is going on. Believe it or not, we don’t always get the complete picture from the initial call out. Sometimes it’s kind of funny (lie the time I got called out on a suspicious death…of a bird!) other times it can cause a lot of arguing. So when we arrive we need to do a walk thru. Basically, the officer will take us a tour of the scene and tell us what they know about it. We want to know certain things like,

• Were any statements made when the officer arrived?
• Was anything moved (officers may need to unload a firearm before we arrive)?
• Did the officer make any alterations (turning on/off lights, opening doors or windows, changing thermostat, etc.)
• What has the officer touched?
• Were there any sounds or smells no longer present?

We also need to get an idea of what we’re about to get into. Are there any hazards on scene? This can be anything from a vicious dog to dirty needles. There may be significant distractions like alarms, distressed family members or irate property owners, or even bad guys hiding somewhere inside. We also assess the types and amount of evidence we need to collect. For example, if we need to collect a couch, bed, or section of wall we’re going to need more help. We may need specialized equipment like an alternate light source, total station, infra-red camera, or simply more criminalists.  We may take notes and photographs during the walk-thru but we don’t collect or process any evidence.

The walk thru is a great opportunity to plan how you’ll process the scene. What will you process first, second, and so on.  Are there certain items that require immediate attention? Some believe that the dead body takes priority but it may be less vulnerable than a suspect shoe print in the snow outside. The walk thru is the best way to make these decisions. It is also an opportunity to “test” any statements made by first responders or witnesses. An officer may believe a death to be natural but if you see an open pill bottle in the trash it may indicate suicide. Officers are trained to disturb only what they have to to secure the scene and tend to victims. As such, they usually have an incomplete picture of the events but that’s to be expected.

As a writer you can use the walk thru to change the direction of the story or test the characters. The call may come in as a suicide but may in fact be a homicide. Gullible or lazy CSIs might accept the things they are told by first responders instead of questioning them in more detail. This can have disastrous effects. You rarely get two chances to process a crime scene.  The challenge is to get it right the first time. The best way to begin on a solid footing is to do a thorough walk thru.