Ambrose discovers that two years prior, Percy Muldoon accidentally shot and killed Bo Lam during a heated confrontation on a boat.
The Sinner - 4x08 "Part VIII" - Series Finale Discussion Thread [S4E8] Part VIII
To protect Percy, her grandmother Meg Muldoon orchestrated a massive cover-up, bribing the Lam family with lucrative fishing permits and a private island to bury Bo. Ambrose discovers that two years prior, Percy Muldoon