Most sex crimes are prosecuted by state and local authorities. Swalwell, a former Democratic representative, resigned from Congress in April following the sexual assault allegations Key points and original sources are listed below.

• Most sex crimes are prosecuted by state and local authorities. The federal agents appeared to be using civil rights statutes to scrutinize Mr. Swalwell’s conduct, a person familiar with the case said.S1

• Swalwell, a former Democratic representative, resigned from Congress in April following the sexual assault allegationsS2