Almost half of officers in charge of the initial stages of a missing persons' inquiry said the training they had received to deal with such investigations was not up to scratch.
A further 51% admitted they had not read the guidelines on how to handle missing persons cases, according to the findings of a report published by the Centre for the Study of Missing Persons at the University of Portsmouth.
Researchers surveyed 215 police sergeants in a large police force in England. All had been in a senior role for at least five years.
Dr Shalev Greene, one of the authors of the report, said: "Decision-making is all too often subjective and inconsistent. One police sergeant might judge the risk of a set of circumstances as high and another might judge the same circumstances as medium.
"The challenge for policing is to remove such subjective measures, or at least place them within a more objective framework that ensures when the power of hindsight is being applied, the decision still stands up to scrutiny."
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White House budget officials outlined the information during a telephone call with reporters given on condition of anonymity.