Gwen Stefani's rocker husband Gavin Rossdale has stepped in to replace Jon Bon Jovi in a new TV cop drama.Bon Jovi was the first choice to play a rock star FBI profilers believe is a serial killer in an upcoming episode of US show Criminal Minds, but the Living on A Prayer star backed out of the project.It's not Rossdale's first acting gig - he appeared in football movie The Game of Their Lives and Keanu Reeves' film Constantine.