Cullen was arrested at a restaurant on December 12, 2003, charged with one count of murder and one count of attempted murder. On December 14, he admitted to homicide detectives Dan Baldwin and Tim Braun that he had murdered Florian Gall and attempted to murder Jin Kyung Han, both patients at Somerset. In addition, Cullen told the detectives that he had murdered as many as 40 patients over his 16-year career. In April 2004, Cullen pled guilty in a New Jersey court to killing 13 patients and attempting to kill two others by lethal injection while employed at Somerset.