According to his bio on Goodreads: "Frank Westworth shares several characteristics with his literary anti-hero, JJ Stoner: they both play mean blues guitar and ride Harley-Davidson motorcycles. Unlike Stoner, Frank hasn't deliberately killed anyone. Instead, Frank edits a monthly classic motorcycle magazine (see RealClassic.co.uk) and has written extensively for the UK motoring press.
Frank's ‘Killing Sisters’ series starts with 'A Last Act Of Charity', continues in 'The Corruption Of Chastity' and wraps up in 'The Redemption Of Charm'.
However, you can start with any of the books in the series; they're written to be enjoyed if you come in halfway through."