James and Jennifer Crumbley were arrested on four counts of manslaughter and pleaded not guilty.
“The defendants were in a better position than anyone in the world to prevent this tragedy, but they did not,” the file said.
CNN has contacted the couple’s lawyers for comment.
In the case, prosecutors said the bond was “properly set” at $ 500,000.
“The facts set out in the brief we submitted to the court today speak for themselves,” Oakland County, Michigan, Assistant Chief Attorney David Williams said in a statement. “And based on these facts, we firmly believe that the bond between James and Jennifer Crumbley has been properly established.”
The record alleges that when the Crumbleys left their son’s school on November 30, more than an hour before the shooting began, they knew their son was depressed and “fascinated by the guns.”
The file details Ethan Crumbley’s state of mind in the six months leading up to the shooting, saying his parents knew he was “sadder than usual”, that his only friend had moved and that he sent his mother disturbing texts about his condition. of spirit.
Prosecutors allege that while their son struggled, his parents spent several hours a night, three to four nights a week, in a barn tending to their horses and that one of the parents was having extramarital affairs.
The file says the defendants were focused on their “own issues”, including “substance abuse issues”.
Prosecutors also allege Ethan Crumbley tortured animals and kept a “baby bird’s head in a jar on his bedroom floor.”
“Instead of paying attention to their son and asking him for help, they bought him a gun,” the file says.
Prosecutors also allege in the record that after the shooting the Crumbleys retained attorneys for themselves but not their son and that Jennifer Crumbley told a colleague and in a text that “the fate of her son is done and that she has to take care of herself. ”
Prosecutors accuse the Crumbleys of ‘willfully disregarding’ clear evidence their son posed a serious risk to other students on the day of the shooting and argue all parents had to do was say school that they had recently bought a gun for him, ask him where the gun was, open his backpack “or just bring it home”.
Prosecutors said their case against the couple was strong and “even stronger” than it was when they were arraigned.
The file joins two versions of a drawing was reportedly made by Ethan Crumbley during a geometry test on the day of the shooting which included a photo of a gun and the words: “Thoughts won’t stop, help me.” Prosecutors allege that Crumbley made “changes” to the design after its discovery.
“In school shootings, it is not uncommon to find evidence of intent and planning after the shooting. What is new in this case is that the defendants have been informed, in graphic form , of the serious risk represented by their son before the shooting, “indicates the file.
A teacher found the drawing on Crumbley’s desk, prosecutors said. This led to school officials holding a meeting with Crumbley and his parents, who were tasked with helping provide counseling to their son within 48 hours, school officials said.
Parents refused to remove their son from school that day and he was allowed to return to class, prosecutors said.
Oxford Community Schools Superintendent Tim Throne said because the suspect had no disciplinary action on his file, school trustees decided to allow him to return to class, rather than sending him to this. that they thought was an empty house.
The Addiction and Mental Health Services Administration, or SAMHSA, has a national helpline – 800-662-HELP (4357) – which provides a free and confidential treatment referral and information in English and French. Spanish 24 hours a day, 7 days a week, every day of the year. .
Carolyn Sung of CNN contributed to this report.