I've always classified Person of Interest as sci-fi, however most sites (such as wikipedia) never mention this and just call it crime and/or drama. My opinion is based on the following in-universe facts:
- There are two AI computer systems which are powerful enough to monitor every camera, microphone, telephone, financial transaction, website and god know what else in the world.
- They both understand all languages flawlessly and can easily communicate with humans.
- At least one of them is shown to be more intelligent than its creator as well as the people who believed they "owned it" (it tricked a bunch of humans into moving it).
- At least one of them has their own agenda which isn't known to anyone.
Now I'm only a programmer, but I don't believe any of this is possible with our current technology, surely this means the show is sci-fi?
without the technology the movie wouldn't exist
: That's also the case in Person of Interest, without the AI they wouldn't be able to intervene and save these people from crime because only the machine is omnipresent enough to spot the people planning it.