U.S. Customs and Border Protection agents used tear gas against roughly 1,000 members of the migrant caravan traveling from Central America. The agents justified their use of the chemical agent after the caravan members turned aggressive and threw rocks. Tear gas has been widely banned in warfare since 1997, as an assaultive and undiscriminating weapon. People affected by tear gas have coughing fits, temporary blindness, and difficulty breathing. In children, several of which were present on Sunday, the effects are more intense and last longer, experts say.

Reporter: Danny McCarthy