Inspector General of the U.S. Capitol Police Michael Bolton
© Anna Moneymaker/Getty ImagesInspector General of the U.S. Capitol Police Michael Bolton testifies on Dec. 7.
About 200 officers have left the U.S. Capitol Police force since the deadly Jan. 6 riot, the department's inspector general Michael Bolton told a Senate panel Tuesday.

A union chief said in April that the force was facing dwindling numbers and low morale, adding later that it would potentially take years to hire and train more officers to recoup its ranks.

Some 140 officers from several departments were injured during the riot. Capitol Police Officer Brian Sicknick died after sustaining injuries while defending the building, and another USCP officer was one of four to die by suicide after responding to the riot.

"I believe it's around 200 or so," Bolton told the Senate Rules & Administration Committee when asked how many officers had left the Capitol Police in the aftermath of Jan. 6.

A USCP spokesperson did not immediately respond to a request to provide the exact number of officers who have left.

Bolton said USCP has only implemented about 30 changes out of 104 recommendations his office offered following the riot.

"Out of 200 security enhancements the department provided to the inspector general, only 61 of those items have supporting documentation to support that those enhancements have occurred," Bolton added.

These security enhancements have included issuing cellphones to officers as a consequence of poor radio communications on Jan. 6.

The Capitol Police "lacks the infrastructure for training, the intelligence gathering and expertise that's needed to prevent future attacks and an overall cultural change," Bolton testified.