First Responders and Forensics: What Really Happens at a Fresh Crime Scene?

Most people love watching shows like CSI, but do you know what forensics really involves? T.V. shows can make the process look so effortless. Here’s what investigators do on every crime scene.

The Initial Call

When someone notifies the authorities that a crime has been committed, the first responders are those who arrive on the scene to assess the damage. Usually, these are police and EMT, but sometimes, it’s just the police. Isolating the crime scene is critical. The faster this occurs, the more accurate the evidence that can be gathered.

Any evidence that leaves the crime scene is evidence that can’t be used to solve the crime. Contamination of evidence also jeopardizes the investigation. Witnesses will be isolated and questioned, individually. Any shoe prints, or gunshot residue will be collected immediately and secured.

Anyone who is injured will be taken to the hospital, but also questioned, if necessary. A police escort may be warranted if there is back-up on the scene.

How Investigators Manage A Crime Scene

While there are many variables in a crime scene, one constant is that it’s impossible for a suspect and a victim to come together in a violent manner and not leave evidence at the scene of the crime.

First things first. Forensics must secure the area and start a “sweep.” They must find as much evidence as they can once they’ve secured the area. This might include blocking off possible escape routes.

The team leader is responsible for the scene, and may require a photographer, a sketch artist, or some type of recorder to record evidence at the scene. Contamination is an important issue too. Since contaminating the evidence can destroy a case, protocols are set up to prevent this from happening.

Sometimes, this digital forensics expert is brought in to analyze any cell phones or electronics devices that have been left at the scene and are at least partially functional. In extreme cases, information can be extracted from a dead phone, but this is more difficult.

Usually, one officer collects all of the evidence, to eliminate or reduce the possibility of evidence being missed. That officer’s name is recorded and he is responsible for all evidence at the scene. All personnel must wear gloves when at the crime scene. Since no one really knows what will become important evidence, almost everything is considered evidence.

Any physical evidence that’s found is taken to a lab for assessment and analysis. The scene is dusted for fingerprints. Today, highly advanced magnetic fingerprint readers and scanners are used to get more accurate “lifts” of prints. These prints can then be run through a central database to find matches.

If the criminal didn’t wear gloves, and is in the database, it’s likely that he will be found as a suspect and a warrant issued for his arrest.

Doctors and EMT Arrival

If medical doctors or EMTs arrive on the scene, or if a coroner arrives at the scene, the medical personnel that are responsible for the bodies cannot remove them until the investigation is over. But, before a medical examiner can remove the bodies, photographs must be taken of the surrounding environment, sketches are made to document everything at the scene, and the body must be preserved in transit.

To preserve delicate things, like fingernails, forensics might place the hands inside paper or plastic bags. Then, the bags are secured which will protect trace evidence, like hair, scratches, or anything else that’s on the body but which cannot be removed or sampled at the scene.

Reconstructing The Crime Scene

This is where the “fun” begins. Investigators have to reconstruct the crime scene to figure out what happened. Usually, this means trying to come up with several hypotheses about what took place. Sometimes, special cameras are brought in to take photos at various angles. Samples are collected from any victims’ bodies, including hair and nail samples to see if any DNA can be found.

Most of what happens at a crime scene to try to reconstruct the events is guesswork, at first. Documentation is also important. Most of the time, the person in charge of the crime scene will close off the area and not allow anyone in.

This is important because, if anyone tampers with the evidence, the criminal might never be caught. While small towns might not have the exact same process as a large city, all crime scene investigation units function on the same basic principles.

With more sophisticated departments, computer modeling can take place to help piece together what might have happened.

Jared Stern, is an experience leader in critical incident management and threat assessment. He also has extensive investigative and risk-mitigation experience. An U.S. Marines veteran, he is the CEO and president of Prudential Associates, a renowned risk management and force-protection company. Mr. Stern enjoys sharing his insights on national radio and TV, as well as by posting on the web. His articles appear on many forensics, science, crime and technology websites and blogs.