Fingerprints have become a critical method in criminal investigations, often helping police link a suspect to the scene of a crime. Their uniqueness can make them seem like conclusive proof, yet mistakes can happen if the evidence is mishandled or misread.
As a defendant, it’s beneficial to understand how fingerprints are gathered, analyzed, and presented in court. Having that knowledge can help you better navigate the legal process and challenge any improper use of fingerprint evidence.
How Fingerprints Are Collected in Criminal Investigations
Collecting fingerprints is one of the central techniques law enforcement officers rely on to connect evidence to possible suspects. Below are some common methods and places where prints might be gathered, along with details about the databases used for identification.
Methods of Collecting Fingerprints
Police often use ink on a card or digital scanning devices to collect a person’s known fingerprints when making an arrest or working in detective offices. Crime scene investigators might lift latent prints from surfaces using special powders, chemicals, or even UV light, depending on the item and the environment.
These unique impressions are crucial in trying to see who touched a specific place or object, helping to narrow down suspects.
Where Fingerprints Are Found
Fingerprints can be left on many surfaces, such as doors, windows, or weapons. Sometimes they’re even found on smaller items like coins, papers, or bottles. Investigators look for out-of-place prints that could belong to someone tied to the crime.
Submitting Prints to Databases
Once prints are collected, law enforcement agencies usually send them to a system like AFIS (Automated Fingerprint Identification System). This database compares the gathered prints with millions of records to see if there’s a match. If a potential match appears, investigators might use that as part of the evidence against a suspect.
Understanding how fingerprints are gathered and examined can help you better navigate the legal process if they’re used as evidence in a criminal case.
The Role of Fingerprints in Linking a Suspect to a Crime
Fingerprints can play a big part in a criminal investigation. If someone’s fingerprint is discovered on a weapon or at a crime scene, it can suggest they handled that item or were in that specific location. However, a fingerprint alone doesn’t automatically prove someone committed a crime because there could be other explanations for its presence.
For this reason, prosecutors must show not just that someone’s print was left behind, but that it’s actually tied to the alleged crime. They can do this by providing context and additional evidence, such as witness testimonies or surveillance footage, to support their argument.
Common Crimes in Which Fingerprints Are Used as Evidence
Fingerprints can serve as powerful evidence in a variety of criminal investigations. Common crimes where fingerprints are used as evidence include:
- Burglaries and Break-Ins: Investigators often dust for prints on doors, windows, or items touched by intruders to see who might have been inside.
- Robberies: Guns, cash registers, and other surfaces are checked for prints to connect a potential suspect to the scene or the items taken.
- Assaults and Homicides: Weapons or objects around the victim may hold prints that help identify who was nearby or involved.
- Drug-Related Offenses: Bags, containers, and drug paraphernalia can pick up prints, indicating who might’ve handled illegal substances.
- Sexual Assault: In these cases, investigators might collect fingerprints from the scene or physical evidence, such as clothing, personal belongings, or objects in the immediate vicinity of the alleged assault. This can help establish whether a suspect was present.
If you’ve been charged with a crime, understanding when and how fingerprint evidence plays a role is essential.
Challenging Fingerprint Evidence in a Criminal Case
Fingerprint evidence may seem strong, but it isn’t always foolproof. Below are several ways defendants facing charges might challenge fingerprint evidence.
Questioning the Collection and Preservation Process
If the scene wasn’t handled properly, prints might be contaminated or mixed up. For example, not wearing gloves or storing evidence incorrectly can ruin the clarity and reliability of the prints. Showing mishandling could weaken the credibility of those prints in court or lead them to be excluded by filing a motion to dismiss.
Arguing Against the Method Used
Different techniques, like dusting or chemical processing, can sometimes produce unclear or partial prints. An expert might explain how small errors in procedure can lead to untrustworthy results. If a print isn’t complete, it may not be strong enough to tie someone to a crime scene.
Disputing the Timing and Location of the Prints
A fingerprint might be perfectly valid, but there could be a simple explanation for how and when it got there. If you regularly visited the place in question before the alleged crime, you could have left the print at an entirely different time. In these cases, providing an alibi for the time the crime allegedly occurred can be incredibly important.
Contact a Tucson Criminal Defense Attorney Today
Are you facing criminal charges in Tucson, Arizona? While fingerprints can serve as evidence, they are often far from conclusive. There is a lot your attorney can do to fight back against the prosecution, so don’t lose hope. If you have questions or need help with a case, contact Katsarelis Law Criminal Defense Attorneys today at (520) 510-0439 to schedule a free consultation with a Tucson criminal defense lawyer.