A method by which a person’s blood can be identified by comparing the DNA profiles of individuals believed to be that person’s parents. Individual DNA makeup is a combination of parental DNA. Siblings will share these patterns while retaining unique DNA markers.

Length differences associated with strands of DNA. These differences vary from person to person, thus providing a means to further identify DNA.

Biological material collected from a rape victim after the fact, to obtain genetic material of the suspected perpetrator.

Any object that contains handwritten or typewritten markings whose source or authenticity are not known, but which is still relevant to the outcome of a legal proceeding.

A wound that is neither an impact wound nor one caused by a projectile; a piercing of the body, usually by a handheld object.

A person whose behavior is largely amoral and asocial, and who is characterized by perverse or impulsive behavior, and a lack of remorse for the consequences of this behavior.

A tool used to aid investigators by providing speculative information about a perpetrator’s psychological makeup. Information from crime scenes is integrated with psychological theory and then cross-referenced against similar crimes. The result is a hypothetical model of the suspect that can include age, occupation, appearance, and personal information ranging from sexual preferences to dietary habits.

Scientists often refer to PCR as “photocopying DNA,” since it allows them to rapidly replicate DNA molecules. The technique usually is employed when a given sample of DNA is too small for forensic testing.

When comparing a known object to one that needs to be identified, analysts will break down photos of each into small quadrants, and compare the respective similarities within those quadrants.