Police say a 21-year-old Robert E. Crimo III was apparently planning the shooting in Highland Park, Illinois, for months. They also revealed he wore women's clothes when he allegedly fired 70 rounds from the roof of a sportswear store. The suspect left numerous red flags on social media about his obsession with violence. Last October, Crimo posted crudely drawn images that show a figure shooting victims with a rifle and then being gunned down by police.