In most crime scenes where DNA evidence is left it can take a number of days before results can be obtained to give a full profile containing accurate data such as age, sex and possibly hair colour. This can then obviously be matched to known DNA from the criminal database. However, this can mean vital time is lost looking at suspects that don’t fit the right profile.
Jan Halamek, a chemistat the University at Albany has developed a much quicker test that could help investigators to narrow down their search to a much smaller age range. They identified chemicals in the blood known as biomarkers. The specific one found is an enzyme called Alkaline phosphatase or ALP and it is associated with bone growth. As we grow ALP peaks at around 18 years of age in women and 19 in men. The enzyme concentration then steadily declines as we age. In a study involving around 200 samples he was able to predict whether the sample was obtained from a person above or below the age of 18 with 99% accuracy. While this is only a very small scale study the results were incredibly encouraging. He is now working on refining the technique to narrow the age identification further, however even this crude method could help investigators to eliminate certain suspects in relation to their age. Also this could save money and time analysing a full DNA profile on suspects in the wrong age category. While Halamek is aware this will never replace full DNA profiling in terms of accurate evidence to convict criminals, the speed at which this could provide information is the over-riding advantage and could compliment the other techniques already in operation.
It is hoped that this test can be modified for use at crime scenes world-wide to give almost instant results similar to some of the current presumptive tests for bodily fluids/explosive chemicals.