Princeton, W.Va. (AP) -- Mercer County Sheriff Danny Wills has resigned amid a federal investigation in which patient records were seized from his office.
Wills, who also is a physician, said in his resignation letter to the county commission that he ran a free clinic out of the sheriff's office.
Wills' letter said he "made legally indefensible mistakes" concerning how he maintained treatment records and ordered and used medications.
Wills' cousin, attorney Mark Wills, provided a copy of the letter to the Bluefield Daily Telegraph.
The sheriff's resignation was effective Tuesday.
The sheriff hasn't been charged with any crime.
Investigators have declined to comment on the probe.
(Copyright 2009 by the Associated Press. All rights reserved.)