A man walked into Smallville Apartments and burglarized several units. When the Smallville crime scene investigators arrived, they found two fingerprints on the counter in one of the units that they believed were left by the perpetrator. The first fingerprint was classified as a loop and the second fingerprint was classified as a whorl. The investigators went back to the police station and looked through their fingerprint cards until they found a local man with a record of driving while under the influence of alcohol who had both loop and whorl fingerprint patterns on the same hand. They arrested the man confident they had found the perpetrator.

Question

ANSWER the following question in the text box and turn in a picture of your drawing:
Why are they wrong to be confident in their arrest and what errors in investigating fingerprints did they make? You should discuss at least three reasons the investigators are incorrect in this situation.
What type of prints were collected from the kitchen counter, patent, plastic, or latent?
Construct an explanation for what technique could be used to lift and evaluate these prints.

Answer 1

The investigators are incorrect in their confidence in identifying and arresting the suspect based on the fingerprints for several reasons:

1. Insufficient Evidence for Identification: Fingerprints can be classified into broad categories like loops, whorls, and arches, but these classifications are not unique to an individual. Many people can share similar fingerprint patterns, and just because the suspect has a similar classification does not mean there is a direct match. Proper forensic analysis requires a detailed comparison of ridge patterns, minutiae points (the unique features found within the fingerprint), and other characteristics.

2. Lack of Context and Corroborating Evidence: The investigation relied solely on the fingerprint classifications without any corroborating evidence linking the suspect to the burglary. For a stronger case, investigators should have gathered additional evidence such as surveillance footage, DNA samples, or eyewitness accounts that could support the claim that the suspect was actually present at the crime scene.

3. Failure to Properly Lift and Analyze the Prints: The investigators did not mention using appropriate techniques to lift and analyze the fingerprints found on the counter. Without using proper lifting techniques, they cannot ensure the prints are usable for comparison, nor can they confirm that the prints were not contaminated or altered.

Regarding the type of prints found on the kitchen counter, these are likely latent prints. Latent prints are impressions that are not visible to the naked eye but can be made visible through proper techniques, as they are formed by the natural oils and sweat from the fingers.

To lift and evaluate latent prints, investigators typically use powdering techniques. The common method includes dusting the surface with a fine powder (usually black or white depending on the surface color) that adheres to the oils in the fingerprint. Once the print is developed, it can be lifted using special adhesive tape and transferred to a card for analysis. Alternatively, chemical methods like super glue fuming or ninhydrin can be employed on non-porous and porous surfaces respectively. These methods allow forensic experts to visualize and compare the fingerprints against known prints in their database, improving the chances of making an accurate identification.

In summary, reliance solely on fingerprint classifications without thorough investigation, context, and proper lifting techniques makes their confidence in the arrest unwarranted.