Effecting the Containment
Remember, what constitutes the true scope and nature of your crime scene may expand beyond that which is readily apparent.
Once you've identified the parameters of your crime scene, you have to physically define them. A cardinal rule is that it's easier to constrict a crime scene than it is to expand one.
"You're not going to screw one up by making it too big," says Lillienfeld. "Guys can be hesitant because of traffic, shy about making a scene a little bit larger than they were anticipating. But almost without fail, you then find physical evidence outside the scene's perimeter."
Greg Dagnan, assistant professor of criminal justice at Missouri Southern State University, teaches multi-level containment. He says the first level is the most basic: that of the crime scene itself. A second level-a second barrier-serves as a buffer zone, allowing for an area where command staff can park their vehicles and investigators can convene without interference. The third level constitutes the outer perimeter, where officers and vehicles can be deployed and road blocks effected.
Coordinating your resources and keeping track of their actions ranks high when it comes to attention to detail. Keep a homicide scene checklist and do things by the numbers. "Little things" such as the absence of a crime log have been successfully exploited by defense lawyers to create doubt as to who has accessed a crime scene and might have contaminated it.
David Newman conducts a variety of crime scene seminars for everyone from first responders to prosecutors and runs the Website www.insidethetape.com. He routinely makes the following recommendations to patrol officers:
"Officers should carry some type of marking devices for physical evidence. I've seen officers use empty Coke cans, business cards, or evidence slips. I encourage them to carry survey flags or things of that nature so that when they have to mark physical evidence they can do so properly so that what they use to mark evidence isn't confused with evidence itself.
"They should also carry with them some type of recording device besides just their cell phone, ideally some type of recording device that can store separate audio or digital files," Newman says. "We'd also like them to have a video camera so that if they arrive at a crime scene and they see something that might be temporary in nature and go away before investigators can get there at least they have a chance to document it. Also, by having an audio recorder instead of just handwritten notes they're able to be much more detailed in the documentation of a scene."
Once the crime scene is cleared of witnesses, victims, suspects, and paramedics, no one should cross the yellow tape and/or enter the crime scene without prior approval of homicide investigators. This prohibition includes the handling patrol unit, assisting units, supervisors, and local dignitaries.
Vernon Geberth is the author of what has been referred to as the "Bible of Homicide"-"Practical Homicide Investigation: Tactics, Procedures and Forensic Techniques." He is also adamant about the need for decisive containments.
"I don't care if you're a billionaire or a bagman," Geberth says. "The same rules apply. It's called constitutional law. What I want from first responders is to act like official representatives of the police department, lock the scene down, stop it in time, and prevent contamination."
Geberth cites ineffectual police presence as a major complication to the JonBenét Ramsey investigation.
"The bottom line is that they (the Boulder Police Department) did not conduct themselves like official first responders," Geberth states. "If you or I were called to the location of an alleged kidnapping and there was a ransom note in the house, what does that make the house? It makes the house a crime scene. That means that we own the house. We would have conducted a search, and we would have found the little girl's body, and all that conditional and transient evidence that was disturbed because the body had been moved multiple times after it was discovered would have been in place, intact, and they would have had an investigation."
Aggravations, Frustrations, and Underminers
At face value, preserving a crime scene doesn't appear to be a difficult task: You put up some crime tape. And you keep people out.
But it can be a lot more complicated than that.
The good news is that, generally speaking, a surprising amount of respect is extended to that flimsy trail of yellow evidence tape. But not everyone is so respectful of this implied force field, and any number of elements and emotions can threaten the integrity of your crime scene.
Perhaps no greater offender is to be found than the looky-lou cop who ventures into a scene with no reason to be there.
"I had an officer-involved shooting where a casing was found outside that had been carried out on the boots of a looky-lou," explains Lillienfeld. "At the same scene, I had three sheriff's department executives walk through a house. They had no reason to be in the house. I could give you a good briefing and you'd know exactly what went on inside the house."
Mindless acts by officers at a crime scene can also frustrate investigators. "I remember a crime scene where it was contained and I found saliva," Lillienfeld explains. "I thought I had DNA evidence. It turned out that one of the officers went into the scene and spit on the street. You'll also find cops putting cigarette butts out on the street, and even using a victim's phone inside a scene."
These are some of the reasons Lillienfeld feels some cops might best serve a homicide investigation by staying away. At the very least he believes in limiting the number of responders to a scene.
"Throwing a bunch of people at a scene is not necessarily the best way to handle it. You want the right people at the scene, people working together, people who are totally aware and understand the whole concept of the investigation so they know what they're looking for. The more people you have to coordinate, the greater the probability that something is going to go wrong," Lillienfeld says.
Another problem is the contamination of the scene by relatives and friends of the victims.
"We had a murder scene where a woman was killed inside a home," recalls Lillienfeld. "Her husband somehow got wind of it at work, and he came tearing up in his car. Nothing was going to stop this poor guy from going in and seeing his murdered wife. I'm in a suit and tie, and I'm on the ground wrestling with this guy, getting my butt kicked. We wound up hooking him up and booking him.
"It was really unfortunate. We had no intention whatsoever of charging this poor guy. You have the emotions, and you have to recognize that is part of the job and part of being mature," Lillienfeld adds. "Sometimes it happens; it isn't the greatest thing in the world for our image, but sometimes you have no choice. The guy contacted us later to apologize for ruining our clothing. He was just out of his mind with grief at the time and later came to his senses, which I think happens more often than not."