A small number of Minnesota police departments are showing interest in a new type of video camera that can be mounted directly on officers' guns, saying it may offer a better view of officer-involved shootings than body cameras. Some law enforcement officials and civil rights groups are skeptical, reports the Star Tribune.

Among the cons, they point out, is that gun cameras start recording only after weapons are removed from holsters and won't capture what led to officers drawing their guns, or other interactions with the public. They also say they should be used only as a complement to body cameras.

Besides the better view, supporters say the pros include lower video storage costs because gun cameras record much less often than body cameras, and a feature in some models that instantly alerts dispatchers and nearby police via wifi and Bluetooth when officers draw their weapons and may need help.

The cameras cost around $500, about the same as some body cameras, and mount under the gun barrel. Some also have high-powered lights so officers do not have to hold both a gun and a flashlight.