A 66-year-old who was detained 18 years ago under the mental health act for the murder of his son in law, has failed to return to a Cambridgeshire hospital after being allowed out to go to Tesco.
He is on twice daily medication for paranoid schizophrenia and police warn he may become aggressive or irritable without his treatment.
Peter Atkins was reported missing by staff at Kneesworth House Hospital in Old North Road, Bassingbourn, at about 4.15pm on Thursday (August 1) after he failed to return from authorised free time to go to Tesco that afternoon.
A public appeal was issued on Friday afternoon but police say they are no further forward in locating him.
DI Dave Savill said: "For Peter to not return from free time is out of character. We know he was seen withdrawing cash at Royston Tesco at 2.10pm and then travelled to Royston town centre by bus, getting off outside Morrisons supermarket in Baldock Street.
"Peter is on twice-daily medication for paranoid schizophrenia and may become aggressive or irritable without his treatment.
"It is very important for anyone who believes they may have seen Peter to contact us as a matter of urgency."
He is described as a white man of a stocky build, with short grey hair and was last seen wearing black trainers, dark blue jeans and a white t-shirt.
It is believed he may have used the rail network to travel from Royston. He could be anywhere in the country but does have links to South Wales.
Anyone with information about Peter's whereabouts should call Cambridgeshire police on 101. Anyone who sees him should call 999 but not approach him due to his unpredictable nature.
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