Crumbley parents turned their son into a killer with 'chaotic and toxic' family life: prosecutors
Oakland County Sheriffs department

James and Jennifer Crumbley not only ignored their son's problems, according to prosecutors, but actively encouraged his violent tendencies.

A new court filing shows Oakland County, Michigan, prosecutors intend to tell jurors the couple exposed Ethan Crumbley to "years of chaotic, toxic conflict" about infidelity and money problems that set him on a pathway to violence that ended in a mass shooting that killed four classmates and wounded seven others, reported the Detroit Free Press.

"Put simply, they created an environment in which their son's violent tendencies flourished," the filing states. "They were aware their son was troubled, and then they bought him a gun."

The parents are charged with involuntary manslaughter for their alleged roles in the Nov. 30 in the mass shooting at Oxford High School, and prosecutors say they bought him the gun he used in the shooting instead of getting him medical help.

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"All they had to do was pay the least bit of attention to their son," prosecutors said in the filing.

The couple exposed Ethan to their infidelities at an early age, such as Jennifer Crumbley taking him to her boyfriend's house when he was 6, and that incident fueled a fight between the parents that was videotaped less than a year before the school shooting that prosecutors want to show to the jury.

"The incident is relevant not only because of (Ethan's) exposure to infidelity and conflict at a young age," the filing states, "but also to show that (he) learned from his parents' words and actions that he could be separated from one of them at any time."

Prosecutors also want to present excerpts from Ethan's journal that describe his troubled family life.

"This morning I woke up to my mom having one of her worst rants about how we have no money and can't pay the bills," the 15-year-old wrote in his 22-page journal, which was discovered the day of the shooting in his backpack. "This just furthers my desire to shoot up the school or do something else. I have no happiness, or optimism left in me as I am a burden to my parents."

"My grades are falling, my parents hate each other, we have no money," Ethan wrote in another entry. "I have zero help for my mental problem and it's causing me to shoot up the f*cking school."

The teenager was charged with first-degree murder and remains jailed until his trial in January, and his parents intend to call him as a witness at their trial, which is scheduled for October.