The first job of any crime scene officer is to secure the scene.Any experienced crime scene officer will tell you that the key to doing the job well is protecting the crime scene. What does that mean? In a nutshell, it means securing the scene, limiting access to only essential personnel, and keeping complete and accurate records of everything that happens there. These steps require work and diligence on your part, but your effort will pay off when you end up with high quality results that will stand up in court.

As you know, the first person on the scene should secure it. However, the first officer on the scene is often confronted with many challenges, especially when dealing with a major crime. Before securing the scene, the officer must establish priorities. For instance, if the officer finds victims needing medical aid, the officer must first provide assistance and call for help. At the same time, the officer must be alert to the presence of suspects and deal with them accordingly.

Once the victims and possible suspects have been taken care of, the first officer can focus on the scene itself. After getting everyone out of the scene, the officer must secure it and prevent anyone from entering. The first officer should also call for a search warrant so that crime scene officers can search the scene and collect evidence. With the scene properly secured, a search warrant can be obtained if needed.

Think carefully when you secure your scene. Keep in mind that it is always better to secure a larger area than you need. You can always shrink the perimeter once you begin processing, but you can’t expand it. In fact, if you do extract evidence from outside of the area you originally secured for your scene, that evidence will be considered questionable in court. After all, who’s to say that that evidence was there when the crime took place? The last thing you want is to have evidence thrown out because you didn’t do your job right. Better to be safe than sorry.

Once you establish the outer perimeter of your scene, you need a way to secure that boundary. Everyone uses crime scene tape for this job, but tape doesn’t necessarily stop people from entering. You should also have officers stationed around the perimeter of the scene to make sure unauthorized people don’t enter. And of course, the larger the scene, the more officers you’re going to need, so plan accordingly.

Remember, the key to preserving the scene is limiting the people who come in and out of it. Often at major scenes, everyone from the general public to the press wants access. You may even have officers and other officials who don’t have a role or job to perform but want “to take a look” for curiosity’s sake. The more people who enter and leave the scene, the more chance you have for contamination. And anyone who enters a crime scene could potentially be subpoenaed. Ask yourself if the people present really need to be there. Then do your best to allow only the essential people in.

There are a number of things you can do to control access to the scene. First, add an additional barrier around the main crime scene. This area becomes the perimeter to your main scene and adds a layer of control. Then keep a record of the activity at the scene. For example, another crime scene officer I know once worked a triple homicide that occurred inside a private residence in South Central Kansas. He marked off the house as the main scene, but they also sealed off the entire property. They then created two separate logs: one for the perimeter and one for the main crime scene. Having the two areas and the two logs allowed them to keep tight control over who entered the scene. For instance, when he needed equipment delivered, the techs entered the perimeter, but they never entered the main scene. By having them sign the perimeter log, he also had a record of exactly when they entered, where they went, and what they did. Whenever anyone entered the interior, they recorded their actions in the interior log. He also took it a step further and had them write up a report describing what they had done in the scene. I can’t stress enough how crucial these logs are. If you don’t keep careful records, the defense lawyers will question the integrity of your evidence.

Along with limiting access to the scene, you should also be vigilant about preventing contamination. You don’t want to bring anything into the scene, nor do you want to take anything out. Be sure to use the proper protective clothing. Change gloves and booties frequently. Collect your booties in a paper sack and send them for processing in case they have any evidence on them. One thing that can make the process easier is a staging area. Set up a tent outside the main crime scene for this purpose. This area gives the officers a convenient place to change into their booties, Tyvek suits, gloves, and masks, and it also lets them do their work out of the view of the public and the press.

In some cases, preventing contamination of the scene can be especially tricky. For example, if you have a victim at a scene, you might have eight or nine first responders. They’re there to try to save that person; they’re not there to preserve a crime scene. In the process of tending to the victim, they may leave behind fingerprints, footprints, and even DNA evidence. There’s nothing you can do after the fact, but you can account for what happened. Interview each of these responders and get a full report of their actions while at the scene. Also make sure you get fingerprints, shoe print patterns, DNA, etc., from them so that any evidence they left behind can be eliminated.

Once you’re finished with the scene, you can release it. But before you do so, stop and think. Are you truly finished? Have you removed and processed all evidence? Have you thoroughly documented the evidence and the entire scene? Make sure you are positive of your answers before you release the scene because once you release it, you’re done.

When you’re dealing with crime scene integrity, the details are important. Take the time to do the job right. Defense lawyers are looking for mistakes to hang their case on. Don’t give them that opportunity.

Dick Warrington is in research and development and a crime scene consultant and training instructor for the Lynn Peavey Company. Dick can be reached at