I would say that advancements in technology have filtered down to those who are committed to fighting crime. The seizure of personal computing devices and disassembling hard drives and scanning through web searches have helped to provide evidence that could go very far in establishing elements of a crime such as motive, opportunity, or means. The idea of being able to simply examine web searches is another instance where technology understanding and advancement have helped authorities be able to ascertain proof of a person’s state of mind, moving them to a person of interest of an accused. Additionally, the ability to share information electronically and in a paperless manner also helps to establish how technology has made fighting crime more efficient, empowering those who fight crime against those who perpetrate it.
I would have to highlight the recent advances in DNA technology as one of the more important crime fighting advances in the last 20 years. It has gotten so much more reliable that dozens of people who were wrongly convicted have been released from prison with compensation, while the maintenance of a prisoner DNA database has helped to capture many criminals who had otherwise gotten away clean. Rapes and murders long since considered cold cases have been solved even decades afterwards. This is better for society and the institution of law as a whole. It gives us more confidence in our verdicts and our courts, and offers better protection from crime. Add to that the knowledge that DNA is so much more accurate probably serves as a deterrent to some criminals, and reduces crime in that way as well.
Combine DNA technology with computerized record keeping and the way in which the states share information and combine their law enforcement efforts, and we have a more effective system for stopping crime.