Death in Paradise: Unlike Father, Unlike Son

The team investigates the shooting of a murder suspect, and there is no shortage of potential culprits, with his angry wife and vengeful brother high on the list. There's just one little puzzle to solve before the cops can even think about whodunit - at the time of the killing, the victim was in police custody, behind three locked doors guarded by Dwayne and JP. So how did the shooter manage to slip through undetected? As if that wasn't enough for Humphrey to worry about, he also has an unexpected visit from his father (guest star James Fox), with whom he doesn't exactly see eye to eye