Paula Bronstein / Getty Images file A new test can determine a
person's age to within nine years from a drop of blood. Crime
scene investigators with little more to go on than a drop of
blood have a new test that can help them determine the age of
the person who was bleeding, according to a study in today's
issue of Current Biology. The test will work even on dried
bloodstains -– perhaps even those revealed by a heat-vision
camera. This could help detectives reopen cases that went cold
years ago. And it's only a matter of time before screenwriters
start working the technology into the plotlines for "Law and
Order" or "C.S.I." The technique, developed by scientists at
Erasmus MC University Medical Center Rotterdam in the
Netherlands, is based on the fact that certain DNA molecules in
some blood cells decrease with age, TG Daily reports: "The
molecules used are residues of the immune system known as sjTREC
molecules. These special DNA molecules are released in blood
cells as a result of the adaptations that hav