A recent study on people who carry guns may shed new light on the case of a black teenager killed by a neighorhood watch volunteer, the Associated Press reported.
George Zimmerman, the volunteer, has said he was acting in self-defense, but Trayvon Martin's family has insisted the case must be investigated as the 17 year old was unarmed. The case has raised outrage and protests, and a federal investigation has been launched.
The study finds that carrying a gun may make someone more likely to perceive threat, and it raises the question: Could the fact that Zimmerman was holding a gun have influenced his belief that Martin was armed?
James Brockmole of the University of Notre Dame and psychology Jessica Witt at Purdue University conducted the study in which they learned that volunteers who held a toy gun and glimpsed fleeting images of people holding an object were biased towards thinking that the object was a gun.
According to the AP, Brockmole stressed that he had no insider information on the shooting, but that it's possible that Zimmerman's perception might have been skewed by being armed.
Past research suggests that people can be more likely to perceive a poorly seen object as a gun if it's held by a black person than by a white person. Martin was black. Zimmerman was Hispanic.
In Brockmole's study, undergraduates at both Notre Dame and Purdue glimpsed scenes of people holding objects and had to decide quickly if the object was a gun. While having a gun nearby didn't make a difference, researchers found that holding a gun made you more likely toward thinking that the object was a gun.
According to Brockmole, "people are primed to act in the world rather than just passively see it. So their minds have to contain information both about what they see and what they might do in response. Evidently, each kind of information can influence the other."
The study is set to be published in the Journal of Experimental Psychology: Human Perception and Performance, and is not intended to support gun control.
According to the AP, Dennis Proffitt, who studies visual perception at the University of Virginia, said that while there are many reasons that someone would act such as Zimmerman did, the effect of holding a gun oneself "could be part of the story" in Florida.
More from GlobalPost: Militia group says it will make citizen's arrest
View all of our Trayvon Martin coverage.