For some in the law enforcement community, the Holy Grail would be a system that allows police to predict crimes and apprehend would-be criminals before those crimes are committed. This concept was popularized by the 2002 film Minority Report.
DNA analysis is a sophisticated (and usually accurate) tool for solving crimes; especially sex offenses, murders and other violent crimes. If police already have a suspect, any traces of DNA left at the crime scene can be analyzed and potentially matched to samples taken from the suspect.
Police interrogation techniques have long been the focus of the national media and the microscope of whistle-blowers. This started back in the early 1900s when police were still using techniques known as the "third-degree," meaning that police were torturing suspects looking for information. Of course, people would say anything just to get the torture to stop, leading to a significant amount of misinformation and false confessions.
We recently discussed how to protect your right to remain silent if cops try to talk to you without an attorney present. But suppose you didn't realize what was happening until it was too late. Or maybe you felt physically threatened or emotionally manipulated into saying what a cop wanted to hear. Now you're worried that the cop tricked you into saying something incriminating.
You thought it wouldn't hurt to tell the cop your side of the story--after all, you have nothing to hide. Being at a party where someone was assaulted doesn't make you a criminal. And anyway, what were you supposed to do--step in and help? So the cops found heroin there, too. You didn't have any on you. And you got out of there before they could ask any questions.