Here's how to identify some crowd control munitions, canisters of which federal agents have left on the ground after deploying them against people in Minnesota. bit.ly/3YWp1jE Graphic by Mark Boswell/The Minnesota Star Tribune

The Minnesota Star Tribune spoke with three experts who reviewed videos and photos of the grenades that Greg Bovino threw on Jan. 21 and determined it was more than likely smoke, though many had thought it was a far more toxic gas, given his "gas, gas, gas" warning. bit.ly/3YWp1jE

It is unclear whether the highly corrosive and carcinogenic hexachloroethane, or HC smoke, has been deployed in the immigration enforcement surge in Minnesota. It was used during the 2020 protests in Portland, Ore., following the Minneapolis police killing of George Floyd.