Well, police still investigate with evidence, but the potential scope of "evidence" is pretty much the whole physical universe. File hashes and TCP packet captures are evidence, DNA fragments are evidence, weather patterns are evidence, in the same way that people's memories are evidence.

Through the decades, the respect shown to eyewitness testimony has generally declined, and crimes with no eyewitness evidence are still expected to be solved.

For offences with a huge online aspect there is no prospect of "getting out there" until you work out where "there" is, because it could be anywhere in the world.