The armed raid on the home of Cherry Groce in 1985 had "serious deficiencies", the inquest into her death has been told.
This was among the conclusions of Assistant Chief Constable West Yorkshire police John Domaille, who produced a 357-page report on the incident.
In summing up the conclusions made in the Domaille report, Dexter Dias QC for the Groce family said:
He reached the conclusion that the most prudent course of action in this case would have been for the operation not to have proceeded forthwith but instead for an intelligence-gathering exercise to take place and that to go ahead as planned with a surprise entry with such lack of information about the layout of the premises and details of the occupants and bearing in mind that the light was on downstairs, he found, would create an adverse risk.
More top news
Explosives experts were called to the nuclear reprocessing site in Cumbria, to help deal with chemical substances.
The arrests were made on suspicion of producing and disseminating pedophilia content on the internet, the country's Justice Ministry said.
The A4-sized sketch originally went for £75 when it was first sold.