Caltrop, Louisiana is a city in Louisiana, approximately two hours from Itta Bena, Mississippi and two and a half hours from Penumbra Plantation. Vincent D'Agosta was placed in the hospital there under a false identity after he was shot in the back with a high-caliber sniper rifle.
Judson Esterhazy traced D'Agosta to Caltrop, using his access to hospital records and correctly surmising that D'Agosta would require a replacement pig heart valve. Esterhazy attempted to murder D'Agosta a second time by injecting muscle relaxant into his IV, but Special Agent Pendergast and Laura Hayward arrived in time to save his life.