There have been a lot of horrible stories about men who lost their temper and ended up hitting a child hard enough to kill him or her. Some of these men have been the boyfriends of the kids' mothers, and they were babysitting the kids while their mothers were at work, at school or out shopping. In a recent news story, a man got mad just because his girlfriend's daughter, who he was babysitting at the time, asked for some food because she was hungry. The guy had been busy at the time and had gotten angry that the little girl had broken his concentration, so he beat her to death.
There have also been quite a few men who have shaken crying babies to death. Some of them were the fathers of the babies, and some were just babysitting. Some of the ones who shook those babies to death claimed that it was an accident and that they hadn't intended to kill the child. But some of them were just selfish cold-blooded sociopathic murderers who had no problem taking a life on purpose.