If you have seen a television or movie murder trial, those theatrical interpretations of an actual murder trial may have included references to gunshot residue. References to gunshot residue (GSR) are common in crime dramas. The police and the prosecution make a big deal about the defendant having GSR on his hands or his close.

However, is GSR evidence the smoking gun that always results in a conviction? In real life murder cases, gunshot residue may or may not be the smoking gun that the state uses to get a conviction.

What is Gunshot Residue?

When a person fires a gun, numerous particles come out of the gun’s muzzle. All of the products from the discharge of the gun are collectively referred to as gunshot residue or GSR. Law enforcement agencies analyze GSR and use the analysis to associate a firearm with an individual.

The presumption is that if a suspect has GSR on his hands or clothing, that he recently fired a gun. Linking the specific particles in the resident to the GSR on the suspect strengthens the prosecution’s case that the suspect filed the gun.

Testing for Gunshot Residue 

Testing for GSR involves lifting samples from a person’s clothing or hands. A laboratory tests the samples for lead, barium, antimony, and other elements known to be present in gunshot residue. If the GSR test is positive, the prosecution alleges it is proof that the person fired a weapon.

However, the presence of GSR does not conclusively prove that the person fired the gun. The prosecution may combine GSR with other circumstantial evidence, such as ballistic evidence and a timeline, to try to prove guilt in a murder trial. However, the evidence can be convincing in the eyes of jurors.

Defenses to GSR Evidence in a Murder Trial

There are some things that your criminal defense lawyer may argue at trial regarding GSR evidence.

A Positive GSR Test is Not a Smoking Gun

Even though you tested positive for gunshot residue, it does not mean that you fired the gun. GSR has the same or similar particles as residue from fireworks or brake pads. Furthermore, you could have transferred the GSR to your handles or clothing because you picked up the gun soon after another person had fired it.

Contaminated GSR Samples

A positive test for gunshot residue could be the result of a contaminated sample. The contamination could have occurred because the sample was not taken for hours after the suspect allegedly fired the gun. During that time, the suspect could have encountered many elements that could have contaminated the sample.

Contamination could result from how the sample was taken. If police officers did not follow proper procedure, the sample could have been contaminated at the police station or a crime scene. 

When samples are not collected at the crime scene before a suspect is handcuffed and transported to the police station, contamination can result from being placed in the police car. There could be GSR on the seats of the police car, on the handcuffs, or in interrogation rooms. Those areas are not cleaned and disinfected after every suspect.

Errors in the Laboratory 

Contamination can also occur in the lab testing the sample. Additionally, labs can make mistakes. The testing could be flawed or human error could result in a false positive for GSR.

Because of the high risk of contamination, criminal defense attorneys can argue that the GSR is not relevant, especially if there is very little evidence to link the suspect to the homicide or other weapons charge.

Fighting Criminal Charges in Dayton

GSR evidence is just one piece of evidence that the prosecution has against you. We must analyze and attack each piece of evidence during our defense. Therefore, the sooner you retain a criminal defense attorney, the better for your case.

Your lawyer reviews, analyzes, and investigates every aspect of your criminal case. For instance, your lawyer analyzes the process used to arrest you and charge you with a crime. 

Did the police officers violate your legal rights through a warrantless search or seizure? Did the officers have probable cause for a stop or an arrest? Were you denied the right to consult with an attorney before interrogation?

If the police officers or any law enforcement agent violated your legal rights, any evidence obtained as a result of the violation could be thrown out of court. Without that evidence, the prosecution may not be able to meet the burden of proof in your case.

In addition to analyzing the evidence and the process, the attorney also analyzes the potential defenses in your case. Did the cops arrest the right person? Were you acting in self-defense?

There are many ways to fight criminal charges. The best way to fight criminal charges is with the help of an experienced criminal lawyer.