Advances in DNA Evidence
In 1985, DNA entered the courtroom for the first time as evidence in a trial, but it wasn't until 1988 that DNA evidence actually sent someone to jail. This is a complex area of forensic science that relies heavily on statistical predictions; in early cases where jurors were hit with reams of evidence heavily laden with mathematical formulas, it was easy for defense attorneys to create doubt in jurors' minds. Since then, a number of advances have allowed criminal investigators to perfect the techniques involved and face down legal challenges to DNA fingerprinting. Improvements include:
- New testing procedures - RFLP analysis required large amounts
of relatively high-quality DNA. Newer procedures require far less DNA and can be completed faster.
- Source of DNA - Science has devised ingenious ways of extracting DNA from sources that used to be too difficult or too contaminated to use.
- Expanded DNA databases - Several countries,
including the United States and Britain, have built elaborate databases with
hundreds of thousands of unique individual DNA profiles. However, these databases also raise questions about privacy. DNA holds a lot more information about a person than fingerprints do. For example, a person's DNA includes information about everything from eye color to genetic defects. Some people fear that the widespread use of DNA databases could encourage governments to discriminate against people because of information encoded in their DNA. However, the DNA used for the FBI's CODIS database is not currently thought to correlate to a person's actual traits.
- Training - Crime labs have developed formal
protocols for handling and processing evidence, reducing the likelihood
of contamination of samples. On the courtroom side, prosecutors have
become more savvy at presenting genetic evidence, and many states have
come up with specific rules governing its admissibility in court cases. See How CSI Works for more details.
- Science education - In recent years, a number of debates have erupted around the world over issues like using DNA evidence, cloning animals or selling genetically modified crops. Since that time, classroom study of DNA and its properties has in many places become more in-depth and widespread.
