The trouble isn’t pre-crime.
The trouble isn’t punishing people for crimes they haven’t committed yet.
As has been pointed out, you don’t need to have a dead body before you can charge someone with a crime. All you need is evidence that they were going to commit a crime, and you can charge them with the attempt to commit a crime.
The trouble with the movie is that the punishment for attempted murder doesn’t make any sense. What’s the point of sticking the pre-murderers into suspended animation? Why not, you know, jail? And, you know, therapy?
There’s no NEED for draconian punishments for attempted murder. Only spur of the moment murders can occur, since any premeditated murderer will be apprehended long before the murder can occur, and since the premeditated murderer knows this they abandon the attempted murder before it happens.
The scales don’t balance. The attempted murder victim isn’t dead, therefore there’s no societal need for the scales to balance by harsh punishment of the perpetrator.
The only reason the suspended animation exists is that it’s science-fictiony and also if Tom Cruise gets frozen without trial there’s no way for him to clear his name. But it makes no sense in the context of a future where pre-crime prevention exists.