Sara McLean

Sara McLean was a serial killer and copycat who poisoned a number of federal government employees in Unforgettable.

Background
Sara was a nurse who worked in the nuclear medical departments of fifteen different hospitals in the Washington, D.C. metropolitan area. She was also a closet psychopath. At some point, she devised a scheme to collect the insurance money of her husband Alex, who she had taken out a $5 million life insurance policy for. Over the past nine years, Sara stockpiled stolen radioactive materials that she had access to through her job, having escaped detection by switching jobs frequently, not stealing from some of the hospitals she worked in, and hacking into the inventory logs of at least five of her workplaces to alter their content. At least four of her former workplaces also assumed the thefts were the work of other employees who were subsequently fired.

Unforgettable
After lethally poisoning four people, including Sam Bower, a friend of Stephen's, Sara puts radioactive material in Alex's lunch and lets it poison him. Because she knows she will be scrutinized if Alex is the last victim in the poisonings, she immediately goes out with a syringe to find another victim to poison. However, the BAU, having deduced the true motive of the attacks, locates her at another federal building. When Prentiss confronts her, Sara grabs a woman and threatens to inject her with the syringe. Prentiss, Lewis, and JJ are unable to take a clean shot, but before she could poison the woman, Rossi shoots Sara from behind, killing her.

Modus Operandi
Because she wanted to make the poisonings look like terrorist attacks, Sara targeted random employees of federal government offices. She would approach them outside of their workplaces and inject radioactive material into their lower backs with a syringe. This would cause them to come down with symptoms of heart attacks, followed by organ failure, thus guaranteeing slow deaths. When she attacked her husband Alex, she didn't inject him with a syringe and instead put the radioactive material in his food as she packaged it. However, he was saved by a gastrointestinal study.

Profile
The unsub is inducing symptoms consistent with heart attacks as a diversion from murders by poisoning. This M.O. is consistent with that of assassinations supposedly committed by the Russian government, but three of the four victims are not typical Russian targets. Thus, it is believed that the unsub is copying this M.O. in order to obscure their true motive for the killings.

This kind of unsub is either an embittered federal employee who was fired, forcibly retired, or otherwise rendered obsolete; someone who intends to profit off of marketing an antidote to the poison once it is discovered; or someone with a personal grudge that is totally unrelated to the federal government, who is using a politically-charged M.O. to divert attention away from said grudge. The unsub also shares characteristics with known product-tamperers and is unconcerned about possible collateral damage as long as they help divert attention away from the true motive of the poisonings. At this point, the unsub does not believe law enforcement is on to him, and media coverage on the poisonings will not be released so as to prevent copycat incidents.

Real-Life Comparison
Sara seems to have been inspired by Stella Nickell, a woman who filled several capsules of Excedrin with lethal cyanide and distributed the tampered bottles throughout a number of stores. Much like Nickell, Sara was hoping to kill her husband through the poisonings in under to collect his insurance money, since authorities would be convinced they were looking for a serial killer. Also, Nickell copied the Tylenol Killer's M.O., while Sara copied the M.O. of poisonings suspected to have been committed by the Russian government; both did so in order to further divert law enforcement attention from her.

Known Victims

 * Aidan O'Harrell
 * Charlene Jorreff
 * Sam Bower
 * Stephen Walker
 * Benjamin Vargas
 * Alex McLean
 * Several unnamed neighbors
 * Unnamed woman

Appearances

 * Season Twelve
 * Unforgettable