Officials say the FBI will help investigate some officer-involved shootings and excessive force complaints against Kansas City police under an agreement with the local police department.

The Kansas City Star reports that authorities announced Thursday that four cases were already under investigation, but they didn't identify the cases.

Under the agreement, the FBI, the U.S. attorney's office, Jackson County prosecutor and the Kansas City police investigations bureau will review an incident and determine whether it should be investigated as a possible violation of federal civil rights or state law.

U.S. Attorney Tammy Dickinson says law enforcement agencies may correctly investigate themselves most of the time, but that self-policing can leave a negative perception in the community.

Officials say the agencies began discussing the arrangement 18 to 24 months ago.