Three Denver sheriff’s deputies have been reassigned as officials investigate why immigration authorities weren’t notified of the release of a jail inmate until an hour after he was already gone.

KMGH-TV reported that Public Safety Director Troy Riggs confirmed the reassignments Wednesday.

A spokeswoman for the sheriff’s department, Daria Serna, says it’s not uncommon to reassign deputies during internal reviews.

Sheriff Patrick Firman has said Denver made a mistake by releasing Ivan Zamarripa-Castaneda of Mexico Saturday before notifying U.S. Immigration and Customs Enforcement.

Denver won’t hold inmates who have posted bond until immigration agents can pick them up unless they have a warrant. However, the sheriff’s department says its policy is to notify ICE once an inmate it’s interested in starts the release process.