A report has found a lack of knowledge about tracking OAP's bus passes "significantly hindered" the search for Daniel McSwiggan earlier this year.
The 69-year-old Alzheimer's sufferer, from Motherwell, went missing in September and was last seen in the Hamilton Low Park area.
Staff had seen the pensioner walking towards the first tee area.
His body was found in Strathclyde Park Golf Course more than two weeks later.
After his family raised concerns about the way police handled the investigation, it was looked at by the Police Investigations and Review Commissioner (PIRC).
The report, published today, said Police Scotland should have treated Mr McSwiggan's disappearance as a higher risk because he suffered from Alzheimer's.
Officers graded the pensioner as "medium risk" instead of "high risk".
The commissioner, Professor John McNeill, said: "There are lessons to be learned from this case.
"In particular, appointing a senior investigating officer, a dedicated person for family contact and a dedicated enquiry team at the earliest stage of the enquiry, may have alleviated family contact difficulties and reduced the family's distress."
The report found officers did not know they could ask the bus company to track a pensioner's movements through his bus pass.
Professor McNeill added: "My investigation found that a number of officers were not aware of the Memorandum of Understanding between the bus company involved and Police Scotland that allowed information on travel concession cards to be used as a way to trace the movement of individuals.
"In my view this lack of knowledge significantly hindered progress of the investigation and should be addressed by an awareness raising exercise within Police Scotland.
"I have also asked Police Scotland to stress to staff the importance of obtaining written statements from significant witnesses and emphasise the importance of early seizure of CCTV footage."