Odds are it is not rooster, rather another hen. Peck wounds are hard to spot and lethal floggings are hard to spot. At one end of my cockyard I have several gamehens each penned in her own brood pen. Until last night I had 4 broody hens with chicks that roamed that area of the cockyard. One of the penned brood hens proved to be a serial killer attacking chicks that came into her pen. Death was not always immediate allowing chicks to go some distance before succumbing to injuries. Close inspect was required to see any external damage. Same hen has demonstrated capacity to be model parent. This forced me to collect broody chicks from all four hens to cut losses.