A Briton has been extradited to the US to face murder charges over the deaths of his wife and baby at their Massachusetts home, police said.
Mr Entwistle agreed to extradition at a London court
Neil Entwistle, 27, is due to appear in court in Massachusetts on Thursday over the deaths last month.
The Briton arrived in America on a private flight in the custody of US marshals.
He is accused of shooting his wife Rachel and child Lillian before flying to the UK to stay with his parents.
The plane carrying Mr Entwistle landed just before 1730 local time at Hanscom Air Force Base in Bedford, north-west of Boston.
Mr Entwistle, who had been staying in Worksop, Nottinghamshire, is due to appear before Framingham District Court at 1400 local time (1900 GMT) on Thursday, a spokeswoman for the Massachusetts Supreme Judicial Court said.
A spokesman for the British Consulate in Boston said it would make contact with Mr Entwistle on his arrival in the US.
"We work to ensure that he has fair and adequate representation," the spokesman said.
"We can't act as legal counsel but we do monitor the case to ensure that he is being treated as a US citizen in similar circumstances would be.
"We can't interfere with the process but we want to be sure he is being treated fairly and maintain contact with the family if they wish."
Lawyer Elliot Weinstein has been assigned to defend Mr Entwistle by the Committee for Public Counsel Services, the Massachusetts body which provides representation for people who cannot afford to hire a private lawyer.
Mr Weinstein expressed concern that the high level of publicity about the case had "created an atmosphere where it will be exceedingly difficult to get a fair trial".
Framingham District Court released documents on Tuesday claiming Mr Entwistle conducted internet searches about euthanasia, suicide and "killing people with a knife" the week before his wife and daughter's deaths.
State trooper Michael Banks also gave a sworn statement that the Entwistles had accumulated a "sizeable amount of debt" that appeared "to have caused a strain in their relationship".
Mrs Entwistle and Lillian were shot dead on 20 January, and their bodies found in a bed at the home two days later.
Mr Entwistle left the US on 21 January, subsequently staying at his parents' home in Worksop, Nottinghamshire.
He was arrested by Metropolitan Police officers at Royal Oak Tube station, in west London, on 9 February, and agreed to be extradited at Bow Street Magistrates' Court a day later.