Forensic scientists distinguish four broad categories of fibre.
Car carpet fiber forensic.
The carpet in his car was very specific to the year make and model of his car and was also found on the boys so they took samples from the car.
Carpet fibers from the car are consistent in all respects with the fibers found on the victim.
More specifically if the victim was transported or assaulted in a vehicle carpet fibers from this vehicle may be collected.
After obtaining a search warrant the police impound the car and submit it to forensic testing.
When it comes to synthetic fibers there are four major types of fibers used for carpeting.
Roux in encyclopedia of forensic sciences second edition 2013.
Natural fibers vary in length depending on the source.
Most of the fiber samples were obtained from collaborative testing services a commercial company.
The carpet fibers found in his house were yellowish green which was the color of the fibers found on the boys and it was discontinued and only made by one company.
Digital records and physical samples.
There are several reasons why synthetic fibers are preferred by many over natural fibers such as wool including cost strength durability and stain resistance.
Fibers can also transfer from a fabric source such as a carpet bed or furniture at a crime scene.
Fiber properties and textile fabrics.
By itself this match is interesting but not conclusive.
In forensic science analysis carpet fibers of unknown origin are often discovered as trace evidence on a victim s person or clothing.
Some labs then extract the dye from the fiber and analyze it by thin layer chromatography hinks says.
Stephen shaw federal bureau of investigations fbi laboratory 703 632 7706 stephen shaw ic fbi gov fbi lab forensic automobile carpet database facd fibers automobile identification.
After all thousands of cars may have this particular carpet.
Most forensic labs currently employ polarized light microscopy to identify fibers.
The establishment of an automotive carpet fiber database may aid investigative efforts.
As discussed previously fibers are considered a form of trace evidence that can be transferred from the clothing of a suspect to the clothing of a victim during the commission of a crime.
Synthetic man made fibers make up the biggest portion of the wall to wall carpet market.
Among the prosecution s forensic evidence were gray carpet fibers collected from duct tape left at two of the crime scenes which an fbi crime lab report claimed exhibited the same.
