Victor Bates said the public are desperate to help with the manhunt but are unable to because they have "no idea" who they are looking for.
"The police's reticence to share anything with the public is not of any help," he said.
"We have got a public in Nottingham that is 99.9% wanting to help and we are not allowed to help because they won't share anything with us."
Mr Bates said he was "vexed" that detectives have still not issued a description of the gunman three days after he opened fire on the 23-year-old probationary officer.
"That poor girl is suffering in hospital after a second emergency operation and we still don't know if we are looking for a black man or a white man.
"We don't know what calibre of weapon has been used or whether the police have an idea of who they are looking for," he added.
Mrs Bates, 64, was shot dead as she defended her daughter Xanthe from an armed robber during a raid on her jewellery store in the Arnold district of Nottingham.
Mr Bates said he felt frustrated by the lack of detail detectives have released since Pc Bown was shot on Monday night and he renewed his call for rank-and-file officers to be given guns.
He said: "If that young Pc and her colleague both had guns there is no way whoever shot her would have dared pull a gun."
Source: Ananova (February 16, 2006)