Other residents include Robert Fulke Greville and his uncle Charles Francis Greville, who improved and expanded Milford Haven as a more commercial and modern settlement, and John Zephaniah Holwell, a surgeon employed by the English East India Company and survivor of the Black Hole of Calcutta, who owned "Castle Hall" in the 1770s. Samuel Lake is remembered for his ambitious bid to complete Milford Docks for £80,000 in a mere seven months in 1880, and his subsequent bankruptcy in 1883 which delayed actual completion for a number of years. An ecclesiastic figure to gain prominence from the town was Frederick Ebenezer Lloyd, an independent Catholic bishop who contributed to the early development of the American Catholic Church. He headed this organization as Primate and Metropolitan from 1920 to his death in 1933. Milford Haven is the birthplace of serial killer John Cooper, who in 2011 was convicted of murdering siblings Richard and Helen Thomas at their Scoveston home near Steynton in 1985, and Peter and Gwenda Dixon on the Pembrokeshire Coast Path near Little Haven in 1989. He was additionally convicted of the rape of a teenager and assault of four others in woodland near the town's Mount Estate in 1996.