Many questions remain about what happened at Hamline Elementary when Chicago Public Schools mistook Secret Service agents for immigration enforcement.

The U.S. Secret Service says its agents visited a Chicago elementary school while investigating a threat. School officials mistakenly said hours before that U.S.

U.S. Immigration and Customs Enforcement agents attempted entry into a Chicago elementary school Friday morning, but were not allowed inside or permitted to speak to anyone inside, Chicago Public Schools officials said.