Which elements are commonly found in gunshot residue?

Gunshot residue (GSR) is typically composed of specific elements that result from the combustion of firearm ammunition. The correct choice identifies the three elements most commonly associated with GSR: lead, barium, and antimony.

Lead is a primary component in many traditional ammunition types, particularly in the primer, which ignites the gunpowder. During firing, lead particles are expelled from the firearm along with the bullet. Barium and antimony are also significant because they are present in the primer materials. When a gun is discharged, these elements are released and can settle on the shooter’s hands or nearby surfaces, making them critical for forensic analysis in identifying potential shooters.

The presence of these three elements effectively serves as evidence when conducted through appropriate testing methods, such as scanning electron microscopy or energy-dispersive X-ray spectroscopy, which can detect their characteristic signatures.

Other potential elements mentioned in the other answer choices, such as iron and copper, do not typically constitute the primary components of gunshot residue, as they are not commonly associated with the chemical processes during the discharge of most firearms. Thus, the identification of lead, barium, and antimony as constituents of GSR is crucial in forensic science for the examination and interpretation of evidence related to