(NewsNation) — Police say they’ve collected more than 100 pieces of evidence from the University of Idaho murder house, but have yet to find the weapon used to kill.

Publicly, authorities have described the weapon as a “fixed-blade.” It hasn’t been confirmed that the knife used was a “Rambo”-style knife, despite multiple reports.

Dave Ellis, one of the world’s foremost experts on knives, told “Banfield” that “Rambo”-style knives have taken on a generic term, and they’re not necessarily common among hunters and fishermen.

“To immediately call it a ‘Rambo’ knife, people jump to conclusions. A ‘Capybara’ would make a lot more sense to me because, to be honest with you, growing up as a kid I used a Capybara as a throwing knife,” Ellis said on “Banfield.”

Former FBI criminal investigations assistant director Chris Swecker also weighed in Monday on “Banfield,” and said from a forensic standpoint, investigators should be able to identify what type of knife was used after looking at the wounds on the murder victims.