Determining the differences between a real handgun and a replica can be a decision law enforcement officers sometimes must make in a matter of seconds.
It happened in Billings Tuesday, when an officer responded to an incident and shot and killed a man who was allegedly pointing a replica Glock 17 handgun at him and others in the area.
It turns out that weapon was a pellet gun. And one Billings gun shop owner says it's almost impossible to tell the difference between the real thing and the replica.
"So somebody points something like this to you, you don't know what's going to be fake or real," said Matt Zimmerman, Butt's Gun Sales owner. "Pretty scary situation."
Just like many items these days, it can be difficult determining a fake gun from a real gun.
"The same grip angle, the same feel, the same weight, the same heft, the same dimensions, the same balance," Zimmerman said.
Zimmerman demonstrated the similarities between a pellet gun replica and a real Glock 17.
"That slide is back slightly, so if I take this gun, it's unloaded," Zimmerman said. "And I put the slide back it's going to look identical to that gun."
Even BB guns today can look like the real thing, and it's hard for law enforcement to tell the difference, Billings Police Chief Rich St. John explained Wednesday at a news conference.
"(The officer) had a weapon pointed at him and needed to make a split second decision," St. John said.
"Why did he have a fake one?" Zimmerman asked. "Does he have a fake one to protect himself or give him the image that he's protecting himself? Or did he have it to intimidate somebody? We don't know."
Zimmerman says some successful target shooters even practice with replica weapons because they're so similar but much less expensive.
Regardless, his advice is to treat every weapon like it's the real thing.