单选题
Violent criminals with something to hide have more
reason than ever to be paranoid about a tap on the shoulder which could send
them to jail. Queensland police are working through a backlog of unsolved
murders with some dramatic success. Greater cooperation between the public and
various law enforcement agencies is playing a role, but new genetic-testing
techniques are the real key to providing the vital evidence to mount a
prosecution. Evidence left behind at the scene of any murder is
guaranteed to outlive the person who left it. A blood, saliva or tissue sample
in the size of a pin, kept dry and out of sunlight, will last several thousand
years. From it, scientific analysis now can tell accurately the sex of the
person who left it. When matched against a sample from a crime
suspect, it can indicate with million-to-one certainty whether the samples come
from the same source. Only twins share identical DNA. So precise is
the technology if the biological parents of a suspect agree to provide a sample,
forensic scientists can work out the rest for themselves without cooperation
from the suspect. Queensland forensic scientists have been
using the DNA testing technology since 1992, and last year they were recognized
internationally for their competence in positive individual identification. That
is part of the reason 20 of Queensland's most puzzling unsolved murders dating
to 1932 are being ac timely investigated. There also have been several recent
arrests for unsolved murders. Forensic evidence was
instrumental in charges being laid over the bashing death of waitress Tasha
Douty on Brampton Island in 1983. Douty's blood-splattered, naked body was
found on a nude sunbathing beach at Dinghy Bay on the island. Footprints in the
sand indicated that the killer had grappled with the 21-year-old mother who had
fled up the beach before being caught and beaten to death.
According to Leo Freney, the supervising forensic scientist at the John Tonge
Centre at Brisbane's Griffith University, DNA testing has become an invaluable
tool for police, its use is in identifying and rejecting suspects. In fact, he
says, it eliminates more people than it convicts. " It is
easily as good as fingerprints for the purpose of identification, " he says. "In
the case of violent crime it is better than fingerprints. You can't
innocently explain things like blood and semen at a crime scene where you may be
able to innocently explain fingerprints. " In Queensland, a person who has been
arrested on suspicion of an offence can be taken before a magistrate and ordered
to provide a sample of body fluid by :force if necessary.
单选题
What is implied in the first sentence of Paragraph 1 ?