A former police sergeant has told the Hillsborough inquests the "primary blame" for the disaster "had to lie with" South Yorkshire Police (SYP).
Stephen Payne said SYP was in charge of the crowd control plan for the 1989 FA Cup semi-final tie, which "failed".
He could see "people's faces squashed against the fences" and said police control "had got it wrong".
Mr Payne also recalled being encouraged to record drunkenness and poor behaviour of fans in his statements.
On the day of the disaster, he had been supervising a group of police constables stationed outside the Leppings Lane End of the stadium in Sheffield.
Ninety-six fans died following a crush at the Liverpool v Nottingham Forest match on 15 April.
Mr Payne said: "I have always tried to be objective about my own thoughts about the disaster and I think I basically, broadly agreed with the results of the Taylor Inquiry, which was that the primary blame had to lie with the police."
'Push people back'
Taylor Inquiry, led by Lord Justice Taylor, was set up in the aftermath of the disaster to establish the cause.
"At the end of the day, the police were the people in charge of the crowd control plan on that day and for whatever reasons, that plan failed," the former SYP officer said.
Mr Payne made his way back to the pitch at about 15:07 after spending up to an hour completing custody paperwork inside the stadium's gymnasium for a fan he had arrested.
In a statement, he said: "I walked quickly across the pitch and it was very evident and obvious to me there was a major problem."
He "got the impression that the radio traffic from police control" was about "a pitch invasion and to push people back into the pens".
The inquest jury was told he then saw "people's faces squashed against the fences".
"They [police control] had got it wrong and people needed to get out of there," the statement added.
During the hearing, Mr Payne said it was "fairly evident" the police plan at the Leppings Lane End was "not robust enough" to deal with the anticipated numbers of late fans.
Asked what he meant by "not robust enough", the former officer said: "Well, it obviously didn't work, did it?"
Jonathan Hough QC, who asks questions on behalf of the coroner, asked whether Mr Payne and his colleagues were told to record evidence of drunkenness.
He said: "I can't remember how it was done - whether it was verbally or in writing, but we were encouraged to ensure that we put evidence in of drunkenness or poor behaviour of fans."
Mr Payne told the hearing his "own personal probity" would not have allowed him to make up evidence and he described his statement as a "factual account".
Coroner Lord Justice Goldring asked: "Were you ever told why you were being encouraged... to mention Liverpool fans and drink? However you were told, were you given a reason?"
Mr Payne replied: "Not that I can recall. It's just a memory I've got of - from somewhere - of that happening."
"I can only guess that it was some sort of protective instinct for the force," he added.
The inquests continue.