Crime scene investigation at a convenience store homicide

Crime Scene Investigation:

A homicide crime has just occurred at a convenience gas station that included the presence of an employee, a mother, and her 15-year-old son who were witnesses of the crime. Upon arrival at the crime scene as a crime scene investigator at 3a.m, I found the deceased victim with an obvious gunshot wound in the chest as the first officer informed me of the present witnesses. As a crime scene investigator, my primary responsibility is the processing of tasks that are related to latent print work. Consequently, my responsibility does not involve any interviews since I'm not the case detective.

Items to Process for Latent Impressions:

While carrying out responsibilities associated with latent print work and other related tasks, there are various items that can be used processed for latent impressions. Upon arrival at this crime scene, I noticed that the scene had already been secured, integrity precautions and procedures were already established, and the necessary measurements had been taken. There are eight visible fixed and non-moveable items in the crime scene that can be considered for processing latent impressions.

The fixed, non-moveable items that I will process for latent impressions are the ripped open cardboard carton on the floor in front of the counter and the typical cardboard six pack container of cold beer bottles on the floor near the beer cooler. These two items are no-moveable items because there is no clear link that they could were significant in the homicide crime. They may be items that the criminal found at the scene of the incident and didn't use them to conduct his/her offense.

The processing for latent impressions at this scene of homicide crime will use two major techniques or processes i.e. porous and non-porous processing techniques. The porous processing technique will be carried out on items like the cardboard carton, notebook paper with the crude map and directions, and the typical cardboard six pack container of cold beer bottles. On the other hand, the non-porous processing technique will be used on the blue steel revolver and the spent bullet since they are the only non-porous items. However, the processing for latent impressions at this crime scene will mainly involve the use of the porous processing techniques.

Since the eight items are significant in the investigation of the crime, all of them will be processed for latent impressions. Processing each of these eight items for latent impressions would be crucial in acquiring necessary information that could be helpful in the arrest of the criminal. Generally, items that can be used for latent processing include porous items like cardboard and paper, non-porous items like metal, blood and paint impressions, digital files, sticky tape, and bullet casings. All the eight items will be processed for latent impressions since they will help in producing fingerprints of the individuals involved in the crime.

The processing of these items for latent impression will be conducted at the state's office for latent print or the latent print section. One of the major processing techniques that will be used is Ninhydrin, which is the widely recognized and recommended process for porous items ("Latent Fingerprints and Impression Evidence," 2011). This procedure will be used for all the porous items like the ripped open cardboard carton, notebook paper, typical cardboard six pack container, spilled cigar box, and the fresh-looking cigarette butt.

The lottery ticket with blood-like impression will be processed for latent impressions through the use of a blood enhancer procedure. Since the caliber revolver and spent bullet are non-porous items, the main latent print procedure that will be used powder processing or power dusting, particularly black magnetic powder because of its effectiveness. While there are several powder colors that are used for powder dusting, black magnetic powder produces the best results.

Determining whether Individuals at the Crime Scene are Witnesses or Criminals:

As part of the investigation of this homicide crime scene, identifying whether the individuals present at the scene are merely witnesses or may have participated in the homicide is very important. This process would involve two major steps i.e. taking their fingerprints and matching them with the latent fingerprints from the items. First, I would take the fingerprints of the employee, the mother, and the 15-year-old boy and then process the visible items for latent impressions. I would then try to match the fingerprints of these individuals with the results of the latent impressions processes.

Packaging Evidence Pertaining to Fingerprint Examination:

One of the major and basic precautions when packaging evidence that pertains to fingerprint analysis is preventing the addition of other fingerprints to the evidence or destroying the existing evidence. In most cases, fingerprints are usually presented on paper, metal, glass, and other smooth surface items. When dealing with articles that contain latents that must be picked, investigators should touch the articles as little as possible and in areas that are least likely to have identifiable latents ("Evidence Collection Guidelines," n.d.).