LONDON (AP) – A Briton accused of killing his wife and infant daughter as they lay in bed at the family’s Massachusetts home is expected to return to the United States swiftly, the Home Office said, after he agreed Friday not to oppose extradition.

Home Secretary Charles Clarke signed an order Friday afternoon authorizing the return of Neil Entwistle, 27, to face charges in Massachusetts. That represented the last legal hurdle in Britain, and Entwistle could be returned at any time.

Entwistle was arrested in London on Thursday on charges of murdering his wife, Rachel, 27, and 9-month-old daughter, Lillian, in their suburban Boston home last month. His attorney, Ben Brandon, told a hearing at Bow Street Magistrates Court that Entwistle wishes to arrive in the U.S. as soon as possible to face the charges.

Also Friday, court documents released in Massachusetts alleged that Entwistle told police three days after the slayings that he didn’t kill his wife and daughter but discovered their bodies in their Hopkinton, Mass., home.

Entwistle allegedly told Hopkinton police in a phone conversation from his parents’ home in England that he left the house at 9 a.m. on Jan. 20, returned two hours later and found Rachel and Lillian dead.

An affidavit filed by Sgt. Joseph Bennett in support of the arrest warrant claimed Entwistle told police he covered up the bodies and then he considered killing himself with a knife, but did not go through with it. He allegedly claimed that he drove to Rachel’s parent’s home in Carver to get one of his father-in-law’s guns to kill himself, but couldn’t get in the home.

Then he said he drove to Logan International Airport in Boston because he wanted to see his parents in England, the affidavit said. Police said Entwistle’s car was found at Logan with keys to his in-laws’ home locked inside.

In London, Entwistle’s legal team said outside the court that Entwistle had agreed to return voluntarily to avoid any “additional distress” to the family of his late wife or to his own parents.

District Judge Anthony Evans told Entwistle that his decision to return would be irrevocable.

“You are agreeing to be sent immediately to the U.S. and there will be no extradition proceedings,” Evans asked Entwistle, who wore gray tracksuit bottoms and a black sweat shirt.

“Yes, that’s right,” Entwistle said, glancing briefly at his father, Cliff Entwistle, as he signed a form consenting to return.

Evans ordered that Entwistle remain in custody until he is sent back to the United States. The suspect smiled briefly at his father, who was the only family member to attend the hearing, as he was led away.

“He wants to cooperate with the authorities in any way that he can, and he is anxious that the delay may cause his late wife’s family and his own additional distress, something he wishes to avoid. He believes that he will receive a fair and a proper hearing in the U.S.A. of these very serious allegations.”

Asked by The Associated Press if Entwistle intended to contest to the charges, Seddon said: “I can’t give any indication of how he is likely to plead.”

Middlesex District Attorney Martha Coakley, speaking on ABC’s “Good Morning America,” said once Entwistle arrives in Massachusetts prosecutors would ask that he be held without bail pending trial, which she said would likely begin in nine to 12 months.

“Whether (the trial) happens a year from now or a year and a half, nothing is going to bring back Rachel and Lilly Rose,” said Joe Flaherty, spokesman for Rachel Entwistle’s family.

Flaherty added the family knows a difficult legal process is just starting.

“It’s going to be a long road for them,” he said. “There will never really be closure in a case like this.”

Coakley told reporters Thursday that an arrest warrant was issued after forensic results indicated the .22-caliber handgun used in the killings was from a collection owned by Entwistle’s father-in-law.

The affidavit said the forensic tests showed Entwistle’s DNA was found on the handle of the alleged murder weapon, and Rachel Entwistle’s DNA was found on the muzzle. Police say she never used the weapon.

Prosecutors believe Entwistle took the gun from his father-in-law’s home, then secretly returned it after the slayings.

Authorities allege Entwistle shot his wife in the head and his daughter in the abdomen as they lay together in bed. The district attorney said it was unclear whether the two were awake or sleeping at the time.

The next day, Entwistle flew to London and stayed with his family in Worksop in central England, authorities said.

A first-degree murder conviction in Massachusetts carries a mandatory sentence of life in prison without parole.

Coakley said Entwistle’s finances had deteriorated after the failure of his Internet businesses, which included a Web site that promised customers as much as $6,000 in monthly earnings and another that offered a manual to help men enlarge their penises.

The affidavit released Friday said he had accumulated tens of thousands of dollars of debts.

Entwistle had met Rachel Souza, an American, in 1999 at the University of York in England, where she was spending a year abroad. They were married in 2003 and moved to the United States last year.