Fernando Angeles Juarez, 64, was shot dead by unidentified gunmen on June 21, the BBC reported on Monday.
The town's 27 police officers and the local public security secretary were detained by federal forces on Sunday.
They were handcuffed and taken for questioning in the state capital Morelia.
More than 100 politicians have been killed across Mexico ahead of general elections on July 1 which will elect a new President, senators and members of the Chamber of Deputies.
?ngeles was the third politician to be killed in just over a week.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
