Mayor Martin J. Walsh will outlaw replica handguns in public spaces at a special ordinance signing tomorrow morning at Twelfth Baptist Church in Roxbury.

Boston Police Commissioner William B. Evans, Twelfth Baptist Rev. Jeffrey Brown, Dan Mulhern, Walsh's advisor on public-safety initiatives, and other officials are expected to attend the 9:30 a.m. event on Warren Street.

Police Commissioner William Evans told the City Council at a recent hearing he was concerned about the potential for an officer to shoot a child playing with a replica gun, as happened in a controversial Cleveland, Ohio, case. The fake guns also have been used in numerous local robberies.

As reported last month by the Herald, the ban will empower police to confiscate any replica handgun not clearly marked as a fake by a federally required orange or red tip on the muzzle.

Police will also be required to notify the parent of any juvenile caught with a replica gun.