A San Francisco man (name withheld in order to protect privacy) was arrested in 2008 on drug charges and while at the Tenderloin police station, was subjected to a strip search, during which nothing was found on his person. However, when he left the station, local law enforcement officers found a plastic bag full of 14 grams of cocaine on the floor near where he had been sitting. This is where his story gets interesting.
Officers determined that the best way to figure out whom the crack cocaine belonged to was to test it using a controversial technique, low-copy number DNA testing. This particular method is often used in so-called ‘cold cases’ or other instances in which it is difficult to use other DNA testing practices because it enables scientists to use a very small amount of genetic material to get results. He was already known to have previous convictions on drug charges and had been sitting near where the bag was discovered. So, it seems only natural that police wanted to blame him.
The problem is not only that low-copy number DNA testing is undependable, but also that his DNA was never found on the bag, they simply couldn’t rule him out. Adding to the problematic issues in this case is the fact that, though he has been exonerated of all wrong-doing, he still spent almost 6 years in federal prison on charges of possession and intent to distribute a controlled substance (21 US Code 841). He was originally sentenced to 5 years and 10 months.