By Tim Castle A BRITISH man accused of shooting dead his wife and infant daughter in Massachusetts agreed yesterday to be extradited to the United States to face charges of murder. Neil Entwistle, 27, was arrested at a London underground train station on Thursday by British detectives and later charged with what U.S. prosecutors said might have been an aborted murder-suicide. During a three-minute hearing at London's Bow Street Magistrates Court, Entwistle's lawyer Judith Seddon said his client had signed a waiver giving his consent to return to the United States as soon as possible. He has consented at the earliest opportunity because he wants to cooperate with the authorities in any way that he can, said Seddon after the hearing. He believes he will receive a fair and proper hearing in the United States on these very serious allegations, she said. U.S. authorities believe Entwistle shot 27-year-old Rachel Souza Entwistle in the head and then turned the .22 calibre gun on his 9-month-old daughter Lillian Rose as the pair lay together in bed early on the morning of Jan. 22. If convicted of first-degree murder charges, he faces life in prison without parole. Middlesex County District Attorney Martha Coakley said Entwistle may have intended a murder-suicide but instead left Boston early the next morning on a British Airways flight and stayed at his family home in Worksop, central England. His wife and daughter were found by police under layers of bedding in the master bedroom at their rented colonial home in Hopkinton, a middle-class suburb about 30 miles (48 km) west of Boston. Coakley said Entwistle, an unemployed computer engineer who drove a BMW, appears to have concealed the depth of his financial troubles from his wife.