Neil Entwistle, whose wife and daughter were found shot to death in their Hopkinton, Mass., home last month, has been arrested in England and charged with murder, officials said.
Middlesex District Attorney Martha Coakley said the slayings of Rachel Entwistle, 27, and her 9-month-old daughter, Lillian, might have originally been planned as a murder-suicide, perhaps motivated by Neil Entwistle's financial difficulties. He had run up a large amount of debt during a move from the United Kingdom to the United States and as a result of several failed Internet ventures, Coakley said at a news conference to announce the arrest.
"He owed money in London. He did not have a job. He did not have a visible means of support," Coakley said. "He was unable to provide income for himself or his family."
Investigators in Middlesex, Mass., believe that at some time on the morning of Friday, Jan. 20, Neil Entwistle shot Rachel in the head with a .22 caliber gun he had previously obtained from his father-in-law, Coakley said. Neil Entwistle then allegedly turned the gun on Lillian, who was lying beside her mother. Entwistle returned the gun to his father-in-law's home and flew to England on a one-way ticket on Jan. 21, authorities believe.
The bodies of Rachel and Lillian were discovered in the couple's bed on Jan. 22.
Neil Entwistle was arrested by British authorities at approximately 7 a.m. ET today after the investigation connected the gun to both Rachel and Neil. Neil Entwistle is charged with two counts of murder, one count of illegal possession of a firearm, and one count of illegal possession of ammunition.
Neil and Rachel met in 1999 while Rachel was studying abroad at York University in England. They had been married for three years, and lived in the United States for four months to five months. In the days before the murder, eBay shut down Neil Entwistle's eBay business, in which he sold get-rich-quick schemes and how-to manuals for pornography, investigators have said.
As of Jan. 12, the couple had been renting the home where Rachel and Lillian were killed.
Coakley said she did not know when Entwistle would be returned to the United States and emphasized that he was innocent until proven guilty.
He is scheduled to appear for an extradition hearing in a London court on Friday.
ABCNews affiliate WCVB-TV and wire services contributed to this report.