During a suicide investigation, what is the primary focus when testing close contacts?

The primary focus during a suicide investigation when testing close contacts is to look for gunshot residue. This is crucial because the presence of gunshot residue on an individual's hands or clothing can indicate whether they discharged a firearm themselves. In cases of suspected suicide involving a gun, determining the presence of gunshot residue can help clarify the circumstances of death.

Testing for gunshot residue is a forensic procedure that can provide concrete evidence regarding the involvement of a person in the shooting incident. If gunshot residue is found, it can support the conclusion that the individual may have fired the weapon, thus contributing to the investigation's findings.

Other considerations, such as finding a motive, interviewing family members, or securing the scene, are also important aspects of a comprehensive investigation but do not pertain directly to the immediate forensic evidence that testing for gunshot residue provides. These factors may contribute to understanding the broader context, but they do not yield the same direct forensic evidence as residue testing does in the context of a shooting.