Complex sentence: He starred as Detective Sergeant Brook in the Radio 4 Extra police series: "Robert Barr-Detective"; series 1: 13 episodes, series 2: 10 episodes, and series 3: 8 episodes (2013 to present).
Split into simpler sentences: He starred as Detective Sergeant Brook in the Radio 4 Extra police series: "Robert Barr-Detective". Season 1-13 episodes, Season 2-10 episodes, Season 3-8 episodes (2013 to present).