Former Customs and Border Patrol chief Gregory Bovino’s use of chemical irritants during the Department of Homeland Security’s “Operation Metro Surge” in Minnesota is the target of a criminal investigation now underway in Hennepin County, the county Attorney’s Office announced yesterday.

County Attorney Mary Moriarty mentioned Bovino’s actions at Monday’s news conference. Footage captured by activist Ben Luhmann shows Bovino throwing a gas canister at protesters and observers in Minneapolis’ Mueller Park on January 21. The canister released green gas that, as Duke University School of Medicine professor and tear gas expert Sven-Eric Jordt told a Mother Jones reporter, may contain the carcinogenic reproductive toxicants lead and chromium.

Moriarty also stated that the office had launched a Transparency and Accountability Project to examine a total of 17 cases, staffed by prosecutors and a civilian investigator from the county office.

The project includes a “portal for community members to share photos and video on any incidents that may involve potentially unlawful conduct by federal agents,” Moriarty said, as well as eyewitness accounts of similar experiences—a response to the federal government’s refusal to provide information that could be used to hold its agents to account.