CLE Forensic Science (Criminalistics) Review: A 6-Week Plan

CLE Forensic Science (Criminalistics) Review: A 6-Week Plan

In PRC's current CLE program this subject is called Forensic Science (older reviewers call it Criminalistics). It carries 15% of your weighted rating and sits on Day 2. It's an easy subject to under-prepare, for two reasons:

1. Many BS Criminology curricula give forensic subjects less time than criminal law and procedure
2. The content is science-heavy — forensic chemistry, ballistics physics, fingerprint pattern analysis, document science. Many criminology graduates entered the field expecting more law and less lab work

That matters because of the CLE floor: under RA 11131, a subject below 60% defers your result even when your weighted average reaches 75%, and you'd have to retake it and score at least 80%.

This post is the focused Forensic Science plan that the CLE pillar guide hands off to.

Suggested study split

PRC doesn't publish item counts per topic, so this is our suggested split of your study time, not an official breakdown:

Forensic chemistry and toxicology

Drill list:

Drug analysis:

• Common drugs of abuse: marijuana, cocaine, methamphetamine, MDMA, heroin
• Methods of detection: TLC, GC-MS, chromatography basics
• Drug Schedules under RA 9165 (Comprehensive Dangerous Drugs Act)
• Classification: depressants, stimulants, hallucinogens, opioids

Forensic chemistry general:

• Blood typing (ABO, Rh) and testing methods
• Gunshot residue (GSR) detection
• Body fluid identification (saliva, semen, urine)
• Trace evidence: hair, fiber, soil
• Glass fragment analysis (refractive index)
• Paint analysis

Toxicology:

• Common poisons (arsenic, cyanide, strychnine)
• Detection methods
• Postmortem changes (toxicology specimens)
• Drug-related deaths analysis

Expect scenario questions that ask which test fits the evidence. Match procedure to evidence type.

Personal identification

Fingerprint identification (heaviest sub-block):

Major patterns:

• Loop (radial loop, ulnar loop) — most common (~65% of fingerprints)
• Whorl (plain, central pocket, double loop, accidental) — ~30%
• Arch (plain, tented) — ~5%

Drill visual pattern recognition until you can name a pattern at a glance.

Minutiae types: ridge ending, bifurcation, dot, lake, island, spur, crossover, bridge.

Henry classification system: numerical formula based on pattern presence in 10 fingerprints.

Dental identification:

• Forensic odontology basics
• Universal Numbering System (1-32 for permanent teeth, A-T for primary)
• FDI Two-Digit System
• Bite mark analysis

DNA identification:

• DNA structure and replication
• Sources of DNA (blood, semen, saliva, hair root)
• PCR amplification basics
• STR (Short Tandem Repeat) loci
• DNA databases (e.g. CODIS in the US)

Ballistics

Three branches:

Internal ballistics: what happens inside the firearm

• Firing mechanism
• Pressure curve
• Bullet velocity at muzzle

External ballistics: bullet flight from muzzle to target

• Trajectory
• Drift, drop, range
• Air resistance

Terminal ballistics: what happens at impact

• Penetration depth
• Wound ballistics
• Tissue damage patterns

Identification of firearms:

• Class characteristics: caliber, rifling pattern (number of lands and grooves, twist direction)
• Individual characteristics: striations from rifling, firing pin impressions, breech face marks
• Comparison microscopy

Common firearms in PHL CLE items: revolvers (.38 caliber), semi-automatic pistols (9mm, .45), shotguns (12 gauge), rifles (.22, M16/AR-15, AK-47).

Questioned documents examination

Drill list:

• Handwriting analysis: characteristics such as slant, spacing and line quality
• Signature comparison
• Typewriter and printer identification
• Ink analysis (chronological, chemical comparison)
• Paper analysis (watermark, fiber composition)
• Erasures and obliterations
• Charred document examination

Practice matching forgery scenarios to the right examination technique.

Forensic photography

• Crime scene photography sequence: overall, mid-range, close-up
• Photographic evidence rules and admissibility
• Ultraviolet, infrared, alternate light source photography
• Chain of custody for photographic evidence
• Macro and microscopic photography
• Film vs digital considerations

Polygraphy

• Theory of polygraph: physiological responses to deception
• Components measured: respiration, blood pressure, electrodermal activity
• Question types: control questions, relevant questions, irrelevant questions
• Examiner training and certification
• Admissibility considerations
• Limitations and counter-arguments

Forensic medicine basics

Overlaps with other subjects but belongs here too:

• Cause vs manner vs mechanism of death
• Postmortem changes: livor mortis, rigor mortis, algor mortis, putrefaction
• Estimation of time of death
• Wound types: incised, lacerated, stab, gunshot
• Asphyxia types

A 6-week Forensic Science plan

Within the 16-week CLE review, give Forensic Science six focused weeks. It's science-heavy, so it needs more time than its 15% weight suggests.

If your school was law-focused

Many BS Criminology programs lean toward law and procedure with lighter forensic coverage. If your school's curriculum was law-focused, expect a gap on your diagnostic.

The fix: the full six weeks, plenty of focused drilling per topic block, and real time on fingerprint pattern recognition.

The fingerprint deep dive

If you have time for one extra deep-dive, make it fingerprint identification:

• Pattern recognition is very teachable with focused practice
• The Henry classification system needs memorization but is finite
• Minutiae identification rewards visual practice

Where Super Tutor fits

A CLE reviewer is coming soon to Super Tutor. If you're also aiming for the PNP, we have a reviewer for the NAPOLCOM PNP Entrance Exam. See every exam Super Tutor covers.

What to read next

The CLE pillar guide covers the full review. Other CLE deep dives: Crime Detection and Investigation, Criminal Law, Correctional Administration.