The Associated Press
This April 14, 2015 file photo provided by the Tulsa County, Okla., Sheriff's Office shows volunteer Deputy Robert Bates. The Tulsa County sheriff placed the agency's spokesman on administrative leave Monday, May 11, 2015, following last month's fatal shooting of a restrained man by Bates. Sheriff Stanley Glanz announced in a statement that Maj. Shannon Clark is on administrative leave, with pay, pending a performance evaluation. The move follows the April 2 shooting of Eric Harris by reserve deputy Robert Bates. Bates, 73, is charged with second-degree manslaughter in the death of Eric Harris. (Tulsa County Sheriff's Office via AP, File)

TULSA, Okla. — A top administrator in the Tulsa County Sheriff's Office is set to resign after an internal memo was leaked indicating he had covered up the inadequate training of a volunteer deputy who fatally shot a restrained man.

Sheriff's office attorney Meredith Baker said Tuesday that Maj. Tom Huckeby plans to resign on Aug. 1. Baker did not explain why.

Huckeby didn't return requests for comment by the Associated Press. Baker says Huckeby is on vacation.

Reserve deputy Robert Bates fatally shot Eric Harris on April 2. The 2009 memo indicated Huckeby was among department officials who pressured critics to ignore Bates' training deficiencies.

An undersheriff featured in the memo has also stepped down since it was leaked.