Pasco County Sheriff's Sgt. Kurt A. Gell resigned Friday in the midst of an internal affairs investigation over his "unarrest" on a drunken driving charge this week.
Early Tuesday, a Hernando County deputy took Gell to jail on suspicion of DUI and then released him after consultation with supervisors.
The Pasco internal affairs investigation focused on whether Gell, a 15-year Sheriff's Office veteran and the agency's officer of the year in 1983, had acted in a way unbecoming to a deputy, misused alcohol off-duty and broken the law.
Gell cited "personal reasons" in his written resignation and said he regretted "having to resign."
Earlier, Hernando Sheriff Tom Mylander decided not to punish Deputy William Steele for the "unarrest" of Gell.
Steele's two immediate supervisors, Sgt. Lanny Corlew and Lt. Robert Henning, were reprimanded for implying that Steele should not arrest Gell.