Rachel Yoder of Fredericksburg, Ohio, was shot Dec. 5 as she drove home in her horse and buggy from a work Christmas party. Police had been treating the investigation as a homicide but it now appears to have been a strange accident, the Wooster (Ohio) Daily Record reported.
"It looks accidental," Holmes County Sheriff Timothy W. Zimmerly said Tuesday.
The man, who turned himself in to police for questioning, said he fired the weapon into the air to clear the barrel before he cleaned the muzzleloader.
The residence is about 1 mile to 1 1/2 miles from the location where the first traces of blood were found on the roadway, Chief Deputy Nathan Fritz told the newspaper.
Zimmerly said a ballistics specialist from the Ohio Bureau of Criminal Identification and Investigation has been called in to assist in the investigation.