Sam Porter is the Chicago detective leading the 4MK task force in J.D. Barker’s trilogy. The Fourth Monkey begins after the Four Monkey Killer is found dead, with another victim still missing. Porter must work from the evidence the killer left behind, including a diary that opens up the case’s earlier history.
The investigation continues through The Fifth to Die and The Sixth Wicked Child. Read the books in order: the cases, Porter’s team, and the information behind the original crimes carry forward rather than resetting with each novel.
Reading Order
See the complete 4MK reading order for all books in the series.