Friday, August 13, 2010

All in the Name of Science by Detective Phil

My name is Phil Melodia and I am a police officer with the San Rafael Police Department. Along with being a police officer one of my other assignments is as a Crime Scene Investigator (CSI).

I am sure that the San Rafael Police Department has had some form of a CSI team since the beginning of time. In fact, we used to be called Field Evidence Technicians before the popularization of the TV show with the same name and all their spin offs.

Ever since, then San Rafael Police Department Chief Cronin, and continuing with every Police Chief since, they have felt that a police department of our size should have a self sufficient CSI team.

In order to have a self sufficient CSI team, the police department has had to provide adequate training for all the CSI members and buy the proper equipment. We finally got rid of the converted ambulance that was our old “CSI van” and got a dedicated CSI van with all the bins and storage compartments, drop down tables, lights, and all the other necessary accouterment for a properly outfitted CSI team.

One of the new pieces of equipment that the police department purchased was an Alternate Light Source (ALS). If you have seen one episode of any of the incarnations of the CSI shows you know exactly what I am talking about. It is when the CSI investigator is using a black light in conjunction with a pair of colored safety glasses in an attempt to locate biological material left behind at the crime scene by the suspect. It makes for dramatic television and it is not nearly as technical as portrayed.

An ultraviolet light source, in conjunction with the properly colored lens, will cause bodily fluids that might not be visible with the naked eye to fluoresce and become readily apparent. Some of the bodily fluids that this technique is used locate is: blood, urine, sweat, saliva, mucus, vaginal secretions and seminal fluids. Basically, if your body produces it and secretes it, the ALS will help you locate it. The ALS is vital tool to be used at any crime scene where a sexual assault took place.

Our first ALS was the Spectroline TFK-100. The sergeant in charge of the CSI team was Sergeant Correa. He assigned me to learn how to use the ALS and teach all the other CSI investigators how to properly use the ALS. I read the instruction booklet from cover to cover.

About this time in my life, my grandfather had recently passed away. I had taken his old v-neck under shirts and brought them home to be used as rags. I came up the brilliant idea that I would take each tee shirt apply a small amount of biological fluid on the tee shirt. I would then write on the label of the tee shirt what the biological fluid was so the CSI investigator could see what each biological fluid looks like while using the ALS.

The first one, blood, was easy. I took a sewing needle sterilized the tip with a lighter and I pricked the tip of my finger. I dropped a few drops of blood on the white tee shirt.

The second one, saliva, was a little more difficult. You never realize how difficult it is to spit on demand until you have to do it. The first time I attempted, the shirt was hanging and the spittle beaded up, rolled down the shirt and fell off the tee shirt and onto the floor. I then placed tee shirt horizontal and I repeated my experiment with much more success.

The third one, urine, was easy. I used the learning experiences I had with the saliva test and duplicated my experiment with urine. I applied a few drops of urine on the third tee shirt.

The following day I facilitated my demonstration of the ALS machine to all my fellow CSI investigators. The training was a smashing success

Since then, the San Rafael Police Department CSI team has used the ALS on numerous crime scenes. I am glad that my blood, sweat, and tears have been utilized to arrest bad guys and put them away for many years.