Fingerprints, DNA testing, blood samples and other crime evidence are much more open to interpretation and judgment than is suggested by television or by the police. As a result, I agree with Roger Koppl and E. James Cowan that there needs to be a Wall of Separation between forensic science and law enforcement:
If you work for the police, you tend to see things from that point of view. Same goes for the prosecution. Usually, it is not a conscious thing. You want to be fair and unbiased, and you think you are. But when the boss hopes you’ll find evidence to support her point of view, your mistakes may lean in that direction.
…Crime labs should produce unbiased scientific evidence. In order to be as unbiased as possible, they should report to independent boards. The boards should represent a diverse group of stakeholders, including a local prosecutor, a prominent defense attorney, a representative from the public defender’s office, a traditional scientist working, perhaps, at a university, and a forensic scientist from another jurisdiction.