What is a fingerprint?
A fingerprint is a one-of-a-kind print that is left in place from the tip of somebodys finger, generally like ridges or canals, sometimes whole ovals if the finger is pressed down fully. The fingerprints that are on your finger is a middle skin layer called the Basal layer, and is then scrunched between the inside which is know as the dermis then the outer skin layer goes over it, or the dermis.
Where does a fingerprint come from?
The basal layer of your finger will always grow faster than the dermis and epidermis wich since the basal layer will grow faster it stretched against its “neighbors” (being the dermis and epidermis) causes the skin on our fingers to buckle which is where our one-of-a-kind fingerprints come from. our nerves have a role in our fingerprints to, their hypothesized which causes stress or pulls on the epidermis.
What different types of fingerprints are there?
theres a couple different types of fingerprints that can be left on surfaces. one type of fingerprint is a Patent print. the patent print is a print on a foreign substance or a smooth object, these prints leave distinct ridges that can be seen to the naked eye without any technological enhancements. the second kind of print is a plastic print and these usually show up when a finger comes in contact with a soft, malleable surface. Wax’s gum, blood, etc. also pick up plastic prints because they will soften and retain to the form of the finger. the 3rd type of print is called a Latent print. Latent prints are prints that are impressed into a secreted surface or objects that are invisible to the naked eye. perspiration which comes from sweat pores found on the ridges of your fingers. (along with moisture, oils, and greases
how are fingerprints helpful to investigations?
Fingerprints are helpful to forensic investigators because they can directly link a print left at a scene to an individual person, because every person’s print is different even if there DNA is the same, like a twin. Fingerprints can also help forensic investigators by using fingerprints in their database to compare them to the print at the scene and see what his criminal background is and everything.
how do you process a fingerprint at a crime scene?
there are multiple ways to process crime scenes although the different types of prints have to be lifted differently. a Patent print is lifted off of a rougher surface as a Latent print is lifted off of a glossier smooth surface. to lift a Latent print you need a camera, magnetic polaroid black powder, Fiber duster, backing cards, and lifting tapes. first you photograph the fingerprint you're about to life, then you apply little black powder to your brush. then you twirl the brush in a circular motion over the print and gently brush off any extra deposits of black powder you don’t need. re-photograph your fingerprint and then apply a small piece over your print and apply pressure. slowly remove your lifting tape and apply to your backing card. then apply name and date.