Newton Abbot police arrested a 26-year-old white British man on Friday on suspicion of murdering Ann Widdecombe, 78, and are holding him in custody.
Officers were called at 11:40 a.m. Thursday to an address in Haytor near Newton Abbot, where the former minister and ex-MEP was found dead with serious injuries.
Devon and Cornwall Police said the case is not being treated as terrorism or as politically motivated, though detectives consulted counter-terrorism officers during initial inquiries.
A cordon and road closures remain in place as specialist teams carry out forensic work, house-to-house inquiries and CCTV checks, while police seek tips, images and footage through a public portal.