US Attorney General William Barr will join hundreds of mourners at Tuesday’s funeral for slain Jersey City hero cop Joseph Seals, according to a report.

The service for Seals — a 40-year-old detective and dad of five who was killed during last week’s rampage by two domestic terrorists — is set to begin at 11 a.m. at St. Aedan’s Church on Bergen Avenue in the North Jersey town.

Barr will be in attendance, tweeted AP’s federal Justice Department reporter.

Hundreds of cops were already stretched down the road at least a half-mile from the church to pay their respects Tuesday morning.