Her crimes unfolded within the enclosed world of French aristocratic inheritance, where patience and access were the only tools required. Over a period of years, she administered poison to members of her own family to consolidate their estates, conducting what amounted to a methodical campaign behind a façade of social respectability. Unconfirmed accounts circulated after her execution that she had refined her methods on hospital patients and animals, lending her case an outsized reputation that helped ignite the broader Affaire des Poisons and a crisis of confidence in Parisian society.

Sencion carried out one of the more unusual mass shootings in recent American history, targeting a civilian restaurant in a deliberate attack that left three National Guard members among the dead. The incident drew attention both for the military casualties and for the apparent randomness of the setting, a midday diner in a mid-sized Nevada city.

The 2013 Boston Marathon bombing brought mass casualties to a public event, killing three people and injuring hundreds more, many of whom suffered permanent injuries including limb loss. Tsarnaev carried out the attack alongside his older brother, and the aftermath — including a days-long manhunt that effectively shut down the Boston metropolitan area — marked one of the most disruptive domestic terrorism incidents in recent American history. He was convicted on all counts and sentenced to death in 2015.