Forensic Science Overview: Fingerprints, Bloodstains, Bodily Fluids, Arson, and Firearms

What are the three types of fingerprints?

Loop, Whorl, Arch

what is the difference between a latent, patent, and plastic fingerprint?

Latent fingerprints are invisible and require special methods to be revealed. Patent prints are visible and left on smooth surfaces. Plastic prints are impressions left on soft materials like clay or wax.

How are fingerprints classified?

classified based on ridge patterns: loops, whorls, and arches. Also categorized in henry system of classification

What are some common methods for collecting latent prints?

Common methods include powder dusting, fuming (superglue), using alternate light sources, or chemical treatments.

What is the importance of the ridge patterns in identifying fingerprints?

Ridge patterns are unique to each individual

What are the basic types of bloodstains?

Passive, Transfer, Impact

How can the angle of impact of a bloodstain be determined?

Measure the width divide it by the length and multiply it by the inverse of sin

What are the factors that influence blood spatter patterns?

Amount of force, the type of surface it lands on, and the angle of projection.

How is the point of origin of bloodstains determined?

By analyzing the direction and angles of the stains to reconstruct the 3D position of the source.

What is the difference between cast-off and projected bloodstains?

Cast-off stains are created by blood flung from an object, while projected stains are caused by direct force to the blood source.

What are the common signs of arson?

Multiple points of origin, accelerant smells, signs of forced entry.

How is the origin of a fire determined?

determined by evaluation of fire patterns and evidence of charring, melting, and distortion of objects

What is the role of accelerants in arson investigations?

Accelerants speed up the burning process and are often used to cause rapid and intense fires.

What are some of the methods used to detect explosive residues?

Methods include chemical swabs, vapor detection, and forensic chemical analysis.

How can fire patterns help in determining the cause of a fire?

burn marks or the shape of burned areas