A research team through the group Physicians for Human Rights combed through social media and news reports to understand exactly what happened during protests against federal immigration agents in the Twin Cities and other parts of the country last winter. Specifically, the researchers looked at the weapons law enforcement used on crowds.

Chemical irritants and projectiles fall into a category called crowd control weapons or less lethal weapons. They come in a variety of products with different mechanisms, and the researchers found that some law enforcement have used them in ways that are especially dangerous to the health and safety of protesters, journalists and passersby.

Scott Reynhout worked on the project with Physicians for Human Rights, and he joined MPR News host Nina Moini to talk about it.