Clifford Robert Olson Jr. (Serial) and Marc Lépine (Mass).

These two murderers have both committed horrible crimes yet they did them in two different ways. Serial murderers tend to have a pattern of victims, or methods to kill them but mass murderers are not as organized. For example, Marc Lepine was a mass murderer and he didnt have a pattern of killing, he decided one day he was going to show up at Montreal's École Polytechnique and shoot women who he accused of being "feminists." However, Clifford Olson planned each murder carefully and repeated it over the years killing eleven children. This is more of a pattern than a disorganised plot to attack a school.

The differences between serial and mass murders are quite obvious,  For example, in the case of revenge, a serial murderer if they were abused by thier mother as a child, they would kill any woman who reminded them of their mother. Whereas a mass murderer, in the case of revenge, if they were fired from their job they would show up to that workplace and shoot workers and perhaps the boss. Or what about for profit? In serial, a woman could poison a line of husbands in order to collect their life insurance money. mass murderers if they were conducting a robbery, they would kill all employees so their was no witnesses.

Clifford olson however had other reasons for his murders because he wasn't setting out to make society better, but to get rid of his sexual desires. Most serial murderers have cooling off periods between murders and use this time to collect themselves and continue. Either hedonistic reasoning or power and control is what dominates over Clifford Olson and is what made him committ his crimes. For example, a hedonistic killer seeks thrills and gets pleasure from killing. And power and control is when their main objective for killing is to gain power over their victim. Such killers are sometimes abused as children, leaving them with feelings of powerlessness and other feelings as adults. This is why Clifford Olsen went for kids.

Murderers will never fully stop but noticing warning signs would be helpful because you could possibly prevent the situation before it happens. If the guards/judges etc. noticed that Clifford was not doing well in jail, had sexually assaulted, and had many crimes on his criminal record that he should not be allowed out, then all those deaths could have been prevented. But with mass murders, sometimes they cannot be prevented because the killer has aready made a plan and will so anything to complete their task.