“The Prosecutor’s Gleam”: Why Fingerprints Are Not the Slam Dunk They Claim to Be

By: John Guidry

Science never seems to prove as much as prosecutors claim. Case in point: Fingerprints. I have seen prosecutors make some pretty ridiculous plea offers when they have incriminating fingerprints. They get that gleam in their eye, like “Guidry, you can’t get your client out of this one—I have prints!”

• The Assumption: Wow, my client must really be guilty this time, right?
• The Reality: Wrong.

The “Match” Myth: When an expert says a print “matches,” they are not saying the prints are identical.

• The Math: They identify 8 to 12 common points (loops and ridges) and make a probability claim. Back in the 1920s, Scotland Yard required 16 points. Today, we settle for less.
• The Problem: Even if it is your print, that evidence is useless if they can’t prove when you put it there.

Did the police find your prints at a crime scene you visited legally?

Timing is everything. Call John today at (407) 423-1117.

The Case: C.P.C. v. State (The Window Pane)

Let’s delve into C.P.C. v. State (Fla. 5th DCA 2015).

• The Crime: A burglary of an apartment. A PS3 was stolen.
• The Entry: The burglar entered through a rear window in an alleyway.
• The Evidence: Police found five latent fingerprints on the bottom of the window pane. Three belonged to C.P.C.
• The Context: C.P.C. was a neighbor. He admitted he lived in the complex and hung out in the alley with friends, often leaning against walls and windows.

There was no other evidence. No stolen goods found on him. No confession. Just the prints.

The Ruling: Public Access = Reasonable Doubt

The Appeals Court overturned the conviction. Why? Because Timing is Everything.

The Court reasoned:

“C.P.C.’s fingerprints may have been placed on the window before the crime took place… [The prints] could also be consistent with C.P.C. leaning against the window, as he claimed.”

The “Public Place” Rule: If a fingerprint is found on the exterior of a building or car accessible to the public, the State must prove the print was left at the time of the crime. Since C.P.C. had innocent access to that alleyway every day, the prints proved nothing.

See also C.E. v. State: A juvenile was convicted of burglarizing a police van because his prints were on the exterior window.

• The Ruling: Conviction overturned. Since the van was parked in public places, the juvenile could have touched it at any time.

John’s 2026 Update: Touch DNA & Ring Cameras

Note: In 2015, they looked for loops and ridges. In 2026, they look for skin cells. The defense is the same.

1. Touch DNA is the New “Smudge” Fingerprints require oil and pressure. Touch DNA only requires a few skin cells.

• The Problem: DNA is “sticky.” You can shake my hand, and then I touch a window, and your DNA ends up on the window (Secondary Transfer).
• The Defense: Just like in C.P.C., we argue that finding your DNA on a door handle or window proves nothing about when or how it got there. It is circumstantial evidence, not proof of guilt.

2. The Camera Defense In 2015, C.P.C. had to rely on his word that he “hung out in the alley.”

• The 2026 Reality: Today, almost every apartment complex has Ring/Nest Cameras.
• The Strategy: If the State claims your print proves you did the burglary at 2:00 AM, but the Ring camera shows a person in a mask wearing gloves at 2:00 AM, the print is proven to be old (stale). We use the absence of video evidence to refute the physical evidence.

3. Exterior vs. Interior The “Public Place” rule is still the gold standard.

• The Tip: If the police say they found your prints/DNA, ask “Where?”
  • On the outside door handle? We can beat that (you could have knocked on the door selling cookies).
  • On the inside of the master bedroom drawer? That is much harder to explain.

Scientific Evidence Requires Context

A fingerprint is just a mark. Without a timestamp, it is just a smudge. Don’t let the prosecutor bully you into a plea deal with “scientific” evidence that doesn’t actually prove a crime.

Call me at (407) 423-1117. Let’s date the evidence.

About John Guidry II

John Guidry II is a seasoned criminal defense attorney and founder of the Law Firm of John P. Guidry II, P.A., located in downtown Orlando next to the Orange County Courthouse, where he has practiced for over 30 years. With more than three decades of experience defending clients throughout Central Florida since 1993, Guidry has successfully defended thousands of cases in Orange, Seminole, Osceola, Brevard, Lake, and Volusia counties. He has built a reputation for his strategic approach to criminal defense, focusing on pretrial motions and case dismissals rather than jury trials.

Guidry earned both his Juris Doctorate and Master of Business Administration from St. Louis University in 1993. He is a member of the Florida Bar and the Florida Association of Criminal Defense Lawyers. His practice encompasses the full spectrum of Florida state criminal charges, with a particular emphasis on achieving favorable outcomes through thorough pretrial preparation and motion practice.

Beyond the courtroom, Guidry is a prolific legal educator who has authored over 400 articles on criminal defense topics. He shares his legal expertise through his popular YouTube channel, Instagram, and TikTok accounts, where he has built a substantial following of people eager to learn about the law. His educational content breaks down complex legal concepts into accessible information for the general public.

When not practicing law, Guidry enjoys tennis and pickleball, and loves to travel. Drawing from his background as a former recording studio owner and music video producer in the Orlando area, he brings a creative perspective to his legal practice and continues to apply his passion for video production to his educational content.