The way the police viewed football (and other) crowds in the 1980s influenced how they policed them. This is why they failed to spot the fatal crush developing until it was too late; it was exacerbated by the police believing that Liverpool fans were attempting to invade the pitch (hence the cordon they maintained near the half-way line while the disaster was at its height), when in fact they were merely trying to escape the fatal crush. This misplaced belief resulted in police pushing fans back into the pens while people still inside them were dying.
A common theme emerges runs through this catalogue of mistakes:
that football matches and crowd events in general in the 1980s were too often seen as a public order problem, instead of a public safety issue. Along with others involved in the study of crowd emergency behavior and safety management, I am very critical of such approaches. … There is almost a sense of moral panic in the way society views crowds, in that they are often seen as vehicles for potential “disorder” or mass panic, despite decades’ worth of research by psychologists finding that such concepts are largely myths, and that crowds often behave much more sensibly than they are usually given credit for. When tragedies happen, it is almost always because of a failure of crowd management, as opposed to any “irrational” behavior on the part of the victims.