It's a lesson taught at every police academy （and by common sense): if someone flees a cri

It's a lesson taught at every police academy (and by common sense): if someone flees a crime scene, there's reason to be suspicious. And if the person hops a flight to London, leaving behind his murdered wife and daughter, and skipping their funeral, the case shouldn't require Sherlock Holmes. And so there was a sense of relief last week when London police arrested Neil Entwistle,27,who will be extradited(引渡) to the United States to face charges of killing his wife, Rachel, and 9-month-old daughter, Lillian, in Hopkinton, Massachusetts, on January 20.

The case had gotten off to a rocky start. Despite repeated searches of the Entwistle home by family, neighbors and police, the bodies went undiscovered for several days, hidden under a pile of quilts in the master bedroom. The resulting uncertainty over the time of deaths led prosecutors to admit early on that they couldn't even tell if Entwistle was in the country at the time of the killings. Although prosecutors immediately called the husband a" person of interest, "they also explored other angles, including whether the killings could be related to the couple's use of eBay, the online marketplace where they'd sold software hut recently stopped making deliveries—leaving buyers complaining of being fooled.

Last week, however, police finished analyzing a gun owned by Rachel's stepfather, and said they found Rachel's DNA on the muzzle(枪口) and Neil's on the handle. Since Neil knew where the gun was kept and had keys to his in-laws home, police believe Neil used the gun to commit the crime and then returned it to his in-laws' gun case be fore heading to the airport.

Police say that Entwistle's only statement about the case was made during the phone call in which authorities informed him that they'd found the bodies. In that conversation, Entwistle—who has not yet entered a plea—told police hem returned home from an errand(差事) and found the bodies himself, then contemplated suicide before changing his mind and buying a one-way ticket to take refuge at his parents' home north of London.

The police say his larger concern, however, was the family's troubled finances. Neil, an unemployed electrical engineer, had racked up thousands of dollars of debt, some of it borrowed to launch a business helping clients set up Web sites. The couple had recently signed a $2,700-a-month lease on a home in Hopkinton, and it's not clear how they'd pay for it. Entwistle hatched the half-completed murder-suicide plan, prosecutors believe, in an attempt to escape his financial problems.

The police met difficulties at the beginning of the case that ______.

A．they couldn't find out Neil's motives of killing

B．they had no idea who might be the criminal

C．the bodies couldn't prove the killing by Neil

D．they could not know when Neil left for London