Clifford Olsen was a serial killer convicted of 13 murders, all of which were children.He would drive around Vancouver picking up his victims, who were usually runaways, then offer them a job and basically a good life, then sexually assault them and murder them. He is so well known because he got away with it for so long. Once caught, he told the police he would tell them where all the bodies were if they paid him $100,000. The police did go along with this, and they did come up with the bodies, but this caused a lot of controversy because the public did not agree with someone benefiting from committing crime.
          Marc Lepine was a mass murdered, he was behind the 1989 Monreal massacre of 28 women at Ecole Polytechnique. He entered the university with a rifle and a knife and walked into room 230, sternly asking the men in the room to leave. Lepine shouted at these women and out of anger shot at them all, leaving six dead. He continued through the school relentlessly shooting all the women he could. One woman was stabbed through her heart several times. Once the fire alarm was set off the gunman put the rifle to his head and shot himself. Marc Lepine's reason behind this mass murder was his issues with feminism. He thought that women getting an education was wrong because they were taking the jobs of men.
          I do not think that there is a possibility of us completely stopping people like this. Sometimes he signs in people do not show til later in life or sometimes they do not seem concerning. Of course we know that, for example, someone who commits pety crimes repeatedly throughout their teenage years is much more likely to move onto more intense crimes but it would be ridiculous and nearly impossible with the resources we have to moniter these people with the tell tale warnings like committing petty crimes or having a bad home life for example. Sometimes the signs do not show until later in a persons life so it can be hard to know who will do these horrid things. It is unrealistic to think that we can stop crime completely.