Finger Printing Case Study
1. What is the composition of latent print residue and how does it affect the viability of latent prints.
The composition of latent finger print residue is the natural secretions of sweat from the eccrine glands that are present in epidermal ridges of the finger. It contains water, ammonia, urea, salts and sugars. They also contain lipids, amino acids and proteins. Other chemicals can be found in the sweat depending on what the person has ingested.
Developing fingerprints takes time and patience. Due to the water content in prints normally you can use fingerprint dust within 12 to 18 hours of the print being placed. After that time period it is recommended you use other forms of development. These forms include, Ninhydrin, Diazafluoren-9-one (DFO), 1,2-Indanedione, Methylthioninhydrin (5-MTN), Cyanoacrylate Fuming, UV Light, and Iodine fuming. Each one of these reacts with one or more of the secretions left behind in the fingerprint.
2. Discuss the techniques available for fingerprinting the deceased. Include methods of fingerprinting the deceased in all forms of decomposition.
Finger printing the deceased comes with its own set of problems depending on a variety of factors such as how long …show more content…
This usually happens when a person is submerged in water for long periods of time. Just as with the early decomposition if the skin is not damaged badly it can be inked and recorded same as a recently deceased person. If the body has been submerged for a long period of time and the epidermis has detached form the dermis you can pull the skin from the back of the finger and pinch the skin. This will smooth out the friction ridge skin, you can then ink and record the ridge detail. If the skin as wrinkled but not pliable you can inject the finger tips with a tissue builder or glycerin, tying a string just above the injection site will keep the fluid from escaping. You can then ink and record the ridge
The composition of latent finger print residue is the natural secretions of sweat from the eccrine glands that are present in epidermal ridges of the finger. It contains water, ammonia, urea, salts and sugars. They also contain lipids, amino acids and proteins. Other chemicals can be found in the sweat depending on what the person has ingested.
Developing fingerprints takes time and patience. Due to the water content in prints normally you can use fingerprint dust within 12 to 18 hours of the print being placed. After that time period it is recommended you use other forms of development. These forms include, Ninhydrin, Diazafluoren-9-one (DFO), 1,2-Indanedione, Methylthioninhydrin (5-MTN), Cyanoacrylate Fuming, UV Light, and Iodine fuming. Each one of these reacts with one or more of the secretions left behind in the fingerprint.
2. Discuss the techniques available for fingerprinting the deceased. Include methods of fingerprinting the deceased in all forms of decomposition.
Finger printing the deceased comes with its own set of problems depending on a variety of factors such as how long …show more content…
This usually happens when a person is submerged in water for long periods of time. Just as with the early decomposition if the skin is not damaged badly it can be inked and recorded same as a recently deceased person. If the body has been submerged for a long period of time and the epidermis has detached form the dermis you can pull the skin from the back of the finger and pinch the skin. This will smooth out the friction ridge skin, you can then ink and record the ridge detail. If the skin as wrinkled but not pliable you can inject the finger tips with a tissue builder or glycerin, tying a string just above the injection site will keep the fluid from escaping. You can then ink and record the ridge