On July 13, 2011, Rebecca Zahau was found dead at her boyfriend's California home — just days after his young son suffered a fatal fall while under her care.

Over the course of three days in August 2009, Angela Simpson callously tormented Terry Neely because she thought he was a police informant.

Throughout the late 1970s and '80s, Ant Hill Kids leader Roch Thériault subjected his followers to an escalating series of horrors, including sexual assault, mutilation, and murder.

In December 1996, Celina Mays vanished without a trace from her New Jersey home just two weeks before she was due to give birth — and she hasn’t been seen since.

In February 2015, an animal rights group released a grainy 99-second video that allegedly showed José Luis Barbero abusing captive dolphins in his care. Days later, he was found dead in an apparent suicide.

In the true story that inspired Pain & Gain, Daniel Lugo and the Sun Gym gang botched multiple kidnapping plots, accidentally killed several of their extortion targets, and brutally disfigured their victims' corpses in a failed attempt to cover up their crimes.

In 1993, Virginia couple John and Lorena Bobbitt became infamous for their "malicious wounding" incident, which Lorena claimed was sparked by years of abuse.

After years of being bullied, 17-year-old Christine Paolilla became friends with two popular girls who helped her fit in at her Texas high school — and then she shot them to death.

Brooke Preston was fatally stabbed by her roommate Randy Herman Jr. in 2017. Then, he claimed that he had been sleepwalking while committing the crime.

In 2011, a 22-year-old conspiracy theorist named Jared Lee Loughner set out to assassinate Rep. Gabby Giffords — and ended up shooting 19 innocent people, leaving six dead.

On November 17, 2016, Brandi Worley brutally murdered both of her children and then tried to kill herself just one day after her husband filed for divorce.