Yellow witness appeal signs on London's streets are to be reviewed to see if they can increase fear of crime.
There are concerns the signs may raise the fear of crime
Scotland Yard says some signs were left up too long and may have created a skewed idea of crime.
Signs for crimes such as murders are to be reviewed to see how effective they are, but police say it is unlikely they will be scrapped altogether.
Instead they will look at how long signs stay up for, where they go and whether they are cost effective.
It is not the first time police in London have looked at whether the yellow signs create public fear.
In 2002, a new more corporate design was introduced and a pledge made to use them more sparingly after one London council asked that it be consulted before any more were used.
Police say a balance needed to be struck between gathering information and potentially raising fear of crime.
And they also had to make sure that those who phoned in were kept up to date with the latest developments.
"One of the things we are most concerned about is that we accept there are signs that have remained too long in a particular location... which has actually potentially given the public a skewed idea of how much crime is happening," said a Metropolitan Police spokesman.
"But it's not a black and white case of whether we keep them or get rid of them. We have to look at the whole thing and see how effective they are, what they cost and if that money could be better spent elsewhere."
A review of the signs, a common sight across London, will be undertaken by the Directorate of Public Affairs.