> The police are under immense pressure to put somebody away or else they're basically telling the public "we have no idea who did this crime". They need to fin

> The police are under immense pressure to put somebody away or else they're basically telling the public "we have no idea who did this crime". They need to find and convict a suspect to instill confidence from the public that they're doing a good job, in order to keep their jobs and their funding. This doesn't mean they need to find the actual criminal, only that they need to appear that they did. they don't even have to put the person away necessarily. an important metric used to evaluate police departments is the clearance rate, which is just the fraction of crimes where they found someone to charge. whether or not the charges stick or get thrown out entirely does not affect this number, and would more typically be used to evaluate the state/district attorney's office. so really all the police need to look good is to collect the bare minimum amount of evidence to charge someone in a case and then move on. if the conviction rate ends up being low or a bunch of charges get thrown out, they can just say the prosecutors are lazy/incompetent. at the same time, the prosecutors can point the finger back at the police and say they throw out so many charges because the police don't collect evidence properly. as long as they drop the weak cases, plea out the middling ones, and take a few slam-dunk cases to court, their numbers will look okay too. all the links in the chain only get examined together in the few high-profile cases that linger in the news.