A top sheriff's official resigned on Monday in Tulsa, Oklahoma, where an unarmed man was shot and killed earlier this month by a volunteer reserve deputy who says he mistook his gun for his Taser.
Sheriff Stanley Glanz announced the resignation of Tim Albin, the undersheriff. A 2009 internal review obtained by NBC News found that Albin had asked employees to modify reviews and training documentation for the volunteer deputy, Robert Bates.
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The same review found that Albin told people who raised concerns about Bates to keep their mouths shut.
The sheriff said he accepted the resignation "as we look as a community for answers to the situation which put Mr. Bates and Mr. Harris on that fatal path."
Bates shot and killed Eric Harris, a suspect in an undercover gun sting, on April 2. Bates has pleaded not guilty to second-degree manslaughter. In an interview on TODAY earlier this month, Bates said the shooting was the biggest regret of his life.
Just a week ago, Albin spoke during a news conference where Glanz deferred to him several times to answer questions from reporters.
This article originally appeared on NBCNews.com.