SCI 114 F2026 study video

Footwear Impressions and Fingerprint Types00:00:00

The video begins by explaining the three types of footwear impressions: latent, patent, and plastic. It covers development methods such as electrostatic lifting, tape lifting, and chemical developers like luminol for blood impressions. The instructor also discusses inked impressions as a development method used in lab to visualize tread marks.

Gait and Fingerprint Minutiae00:04:00

The instructor clarifies that gait is not an individualizing characteristic and lacks rigorous scientific backing compared to other forensic evidence. She then explains that students do not need to memorize every minutiae for the exam but should know basic ones like bifurcation, dot, and enclosure, as vocabulary is important for written responses.

Hair Microscopy and Crime Scene Investigation00:09:10

This section addresses why the medulla appears dark under a microscope due to light refraction and air bubbles, and briefly touches on refractive index and birefringence. It also explains why crime scene investigators can be called at any time since crimes happen at all hours, and how lead officers secure scenes before technicians arrive to collect evidence.

Blood Testing and Evidence Packaging00:26:20

The instructor reviews why presumptive tests are run first because they are quick and determine whether to send evidence to the lab. She explains false positives versus false negatives and uses the Dingo baby case as an ethical example. The section also covers packaging rules: organic wet items like blood go in paper bags to prevent molding, while arson debris goes in airtight metal cans to trap gases for analysis.

Fingerprints, Hair Structure, and Fibers00:38:10

This part reviews the three fingerprint classes: loops, whorls, and arches, and how to identify minutiae like bifurcations and dots. It covers hair anatomy including the cuticle, cortex, and medulla, as well as growth phases (anagen, catagen, telogen). For fibers, it discusses direct, secondary, and tertiary transfer, Locard's exchange principle, and the difference between natural, man-made, and mineral fibers.

Footwear, Tire Impressions, and Study Tips00:57:00

The instructor explains how tire impressions can narrow down vehicle body styles and tire brands through databases. She briefly discusses bite mark analysis and its unreliability. The video concludes with grading weight information (midterm is 15% of the grade), study advice like using flashcards and concept maps, and confirmation that the exam will consist mainly of multiple choice and true/false questions.