A volunteer medic who was hit in the chest with a tear gas canister fired by a federal officer during racial injustice protests in Portland, Oregon, last summer has sued U.S. Department of Homeland Security officials and agents. The lawsuit filed in federal court Monday says Nate Cohen had just doused a tear gas canister that had landed next to journalists and legal observers on July 26 when he was hit directly above the heart by a canister. Tear gas canisters aren't meant to be used as an impact weapon, which can cause serious injury or death. The Department of Homeland Security says it cannot comment on pending litigation.