Few families experience the amount of tragedy that the Gilberts have. 52-year-old Mari Gilbert became a murder victim advocate after her Craigslist-escort daughter Shannan's life was taken by a serial killer in May 2010. Little did she know, a murderer was lurking in her own family as well.

On July 23, 2016, Mari was stabbed 227 times with a 15-inch butcher knife. Then she was beaten with a fire extinguisher, sprayed with the foam, stripped and robbed of her jewelry after her death. Who would commit such a horrible crime against someone that seemed so selfless? Her own daughter, Sarra Gilbert, Shannan's sister. The young woman slaughtered her mom inside her apartment building on Warren Street in Ellenville, New York.

sarra gilbert, times herald-record
Times Herald-Record

Sarra Gilbert.

But why would she do something like that? Her lawyer claimed it was due to several years of sexual abuse at the hands of Mari's boyfriend, plus mental illness, schizophrenia, and drug abuse. She also reportedly thought her mom was a demon because she practiced "black magic." Her remaining sister, Stevie Smith, disagreed. “[She's] wicked,” said Stevie in a letter read in court. “The way she took my mom out of this world is beyond human. This was not a result of mental illness. This was the result of long-term hate and not a mental breakdown.” Stevie said that Sarra “tormented and belittled their mother for years before she killed her," not the other way around.

The judge agreed with Stevie. One year after the slaying, on Aug. 4, 2017, Sarra was sentenced to 25 years in prison, and the judge said he'll do his best to make sure the 28-year-old never walks free again, according to DailyFreeman.com. The whole thing is such a great tragedy, and our hearts go out to Mari's remaining family.