Other Undergraduate 1,656 words

Mock Crime Scene Investigation: Analysis and Evidence Review

~9 min read

Abstract

This paper presents a mock crime scene investigation based on a fictional scenario involving four elementary school boys in South Park, Colorado. The paper walks through the full investigative process: evidence collection and chain of custody, forensic analysis of blood, hair, footprints, and drug samples, and a suspect inclusion/exclusion matrix. Blood typing via precipitin testing, footprint measurement comparison, and drug screening are documented in detail. The paper concludes with a crime scene recreation that integrates physical evidence with witness interviews, ultimately identifying a likely perpetrator while acknowledging the complexity of group involvement and the absence of premeditation.

📝 How to Write This Type of Paper Writing guide — click to expand

▼

What makes this paper effective

The paper follows a logical, procedural structure that mirrors an actual forensic investigation, moving from scene description to evidence collection to lab analysis to conclusion.
It effectively uses tabular data — blood typing results, footprint measurements, and a suspect matrix — to present comparative forensic evidence in a clear, organized format.
The crime scene recreation section demonstrates critical thinking by integrating physical evidence with interview data, avoiding a purely mechanical interpretation of lab results.

Key academic technique demonstrated

This paper demonstrates the use of a suspect inclusion/exclusion matrix as an analytical tool. By systematically evaluating each suspect across four evidence categories (hair, shoe prints, drugs, and blood), the paper avoids confirmation bias and shows how forensic conclusions must be built from converging evidence rather than a single data point. This multi-variable approach is a foundational technique in forensic science methodology.

Structure breakdown

The paper opens with a narrative crime scenario, then catalogs evidence by type (drugs, hair, blood). The forensic analysis section covers each evidence category with documented procedures and observations. A suspect matrix summarizes inclusion/exclusion results. The paper closes with a narrative crime scene recreation that synthesizes all findings into a probable account of events. This structure reflects a standard forensic case report format.

Crime Scenario and Initial Response

Date: November 8, 2011
Location: South Park, Colorado — a small town on the foothills of the Rocky Mountains.

A teacher at South Park Elementary School called the police on the evening of November 1, 2011, at approximately 17:56. She noticed four boys who habitually spent time together entering the school after hours. Based on her recollection, she identified all four boys as 4th graders: Stan Marsh, Kyle Broflovski, Eric Cartman, and Kenny McCormick. When police arrived, they moved into a classroom and found Kenny with a sword through his face. The other three boys — identified as Stan, Cartman, and Kyle — were standing in the room pointing at Kenny. Kyle turned to the police and shouted, "Oh my God, they killed Kenny! You bastards." The boys then fled the room. Officers secured the room, collected evidence samples, and sent Kenny's body to the morgue.

At first assessment, the scene appeared to involve some kind of a childish prank gone wrong. Officers immediately bagged the sword and covered the hilt for fingerprint processing. They also worked to identify any debris or material around the body and swabbed for blood. Kenny's blood was typed for further matching, and officers requested a detailed report on any fibers or clothing found at or missing from the scene. The police then secured search warrants for all of the boys' homes and collected the evidence listed below.

For general background on crime scene investigation procedures, including evidence collection and chain of custody, the Wikipedia overview provides a useful reference.

Evidence was collected in three major categories: D (Drugs), H (Hair), and B (Blood). Collection was as follows:

Drug Samples (D): D1 (Powder from scene); D2 (from scene); D3 (Victim); D4 (Cartman); D5 (Kyle); D6 (Stan). These samples were taken to determine whether any traces of unknown powders or substances could be matched from the scene to the suspects, and to establish potential patterns of behavior or substance use.

Hair Samples (H): H1 (Crime scene); H2 (Crime scene); H3 (Victim); H4 (Cartman); H5 (Kyle); H6 (Stan). Hair samples were taken to identify potential matches between the scene and the suspects, and to help establish each individual's position at the time of the crime.

Blood Samples (B): B1 (Crime scene); B2 (Crime scene); B3 (Victim); B4 (Cartman); B5 (Kyle); B6 (Stan). Blood samples were taken to match blood found near the victim, and to determine whether blood transfer had occurred between victim and suspect, or vice versa.

Evidence Inventory and Chain of Custody

Eighteen pieces of D, H, and B evidence were logged as non-photographic evidence (D, H, and B samples 1–6 consecutively). D3 is missing from the Evidence Log Sheet but was entered into evidence and signed by an officer on November 8. Other than this discrepancy, the chain of custody is complete for all non-photographic evidence.

Seventeen photographs were taken and seventeen photographs were logged as evidence. Crime scene photos are grouped as follows:

Footprint measurements were recorded for crime scene samples and compared against shoe samples collected from each suspect. Results are summarized below:

Crime Scene Sample: Long Length 26 cm; Short Length 12 cm; Long Width 9 cm; Short Width 6 cm.
Kyle — Black Converse (ID 11811F3): Long Length 26 cm; Short Length 12 cm; Long Width 8.5 cm; Short Width 5.5 cm.
Stan — Pink/Blue Converse (ID 11811F4): Long Length 26.5 cm; Short Length 11 cm; Long Width 9 cm; Short Width 5.5 cm.
Cartman — Green Converse (ID 11711F2): Long Length 26.5 cm; Short Length 11 cm; Long Width 9 cm; Short Width 6 cm.
Victim (Kenny) — Puma (ID 11711F1): Long Length 27 cm; Short Length 9 cm; Long Width 8 cm; Short Width 5 cm.

Note: Yellow-highlighted entries indicate the closest match; minor variability may be accounted for by individual walking or standing posture.

Drug samples were screened from two crime scene locations and from each suspect and the victim. Results are as follows:

Crime Scene (Sample 1): Mordeline, Morgis
Crime Scene (Sample 2): Nitric Acid, Ferric Chloride
Kyle: Froese, Meoke
Stan: Acetomin, Baking Soda
Cartman: Acetomin, Sugar
Victim (Kenny): Salt, Aspirin

Forensic Analysis of Evidence

Six blood samples required testing: the victim's blood (Kenny, 11811B3); Blood #1 found at scene (11811B2); Blood #2 found at scene (11811B1); Suspect 1 — Stan (11811B6); Suspect 2 — Cartman (11811B4); and Suspect 3 — Kyle (11811B5).

The ABO blood typing system uses antigen-antibody reactions to classify blood, forming the basis of the precipitin test used here.

Procedure:

Observations:

Kenny (11811B3): Anti-A — No clumping; Anti-B — No clumping; Anti-D — No clumping; Result: O−
Blood #1 at scene (11811B2): Anti-A — Clumping; Anti-B — Clumping; Anti-D — Clumping; Result: AB+
Blood #2 at scene (11811B1): Anti-A — No clumping; Anti-B — No clumping; Anti-D — No clumping; Result: O−
Stan (11811B6): Anti-A — No clumping; Anti-B — Clumping; Anti-D — No clumping; Result: B−
Cartman (11811B4): Anti-A — Clumping; Anti-B — No clumping; Anti-D — Clumping; Result: A+
Kyle (11811B5): Anti-A — Clumping; Anti-B — Clumping; Anti-D — Clumping; Result: AB+

From these results:

The only hair recovered was that of the victim. No matches to any suspect were established, and hair evidence is therefore not relevant to suspect identification in this case.

The following processing methods would be applied to each evidence type:

Fingerprints: No fingerprints were taken at the scene, but dusting and tape-lifting would have been employed had evidence been present, followed by comparison of ridge patterns against suspects or a database.

Hair: If a root was attached, DNA analysis using PCR technology would be conducted. If not, microscopic examination using 15–20 representative samples for comparison would be performed.

Blood: RFLP, DNA analysis, precipitin testing, and comparative analysis.

Footprints: Precise measurements and castings, followed by comparison against suspects or a national database.

Drugs: Spectrographic or chemical analysis, depending on the type and physical form of the substance (powder, liquid, solid, etc.) (Schiro, 2010).

2 Locked Sections · 330 words remaining

Suspect Inclusion and Exclusion · 110 words

"Suspect matrix comparing evidence across all four boys"

Crime Scene Recreation and Conclusion · 220 words

"Narrative reconstruction integrating physical and interview evidence"

You’re 55% through this paper. Sign up to read the remaining 2 sections.

130,000+ paper examples AI writing assistant Citation generator Cancel anytime

Key Concepts in This Paper

Chain of Custody Precipitin Test Blood Typing Footprint Analysis Drug Screening Hair Evidence Suspect Matrix Crime Scene Recreation Forensic Procedure Evidence Collection