In a recorded manifesto played in court on Thursday, Ethan Crumbley stated that he was "going to have so much fun" shooting his classmates the night before he murdered four students and injured seven others.

Relatives of Crumbley's victims who attended his sentencing hearing were horrified to hear him boast that he would be the next school gunman and that he needed to "teach them a lesson" by carrying out the massacre at Oxford School.

Michigan School Shooting Suspect's Journal Reveals Obsession to Violence

Prosecutors told CNN on Thursday that Crumbley, who has pleaded guilty to the atrocity, made the startling statements in a manifesto he recorded the night before carrying out his devastating plan. Crumbley indicated he would attempt to shoot as many individuals as possible. Phoebe Arthur was the first victim fired by Crumbley; she survived but was severely injured.

Crumbley stated in his letter that he did not wish to perish and wished to be remembered. Additionally, prosecutors presented evidence and witness testimony indicating that the mass shooter delighted in torturing and murdering young birds.

In text messages sent to a close friend months before the school massacre, Crumbley expressed a desire to abduct, rape, torment, murder, and dismember a classmate and described drowning children as "the greatest sensation."

The courtroom was also shown a silent video of the actual massacre, in which Crumbley emerged from a restroom armed with a pistol and opened fire on students as they changed classes. Several victims' families wept discreetly as they witnessed the homicides of their loved ones. The prosecution requested that the adolescent be sentenced to life without the possibility of parole.

Never-before-seen video footage of the shooting was also presented by the prosecution. Students who witnessed the carnage are also anticipated to provide testimony, USA Today reported. The prosecution will attempt to persuade the judge that the shooter merits a life sentence without parole for his offenses. Families of the victims are anticipated to be present in court.

The video and student testimony are part of Crumbley's so-called Miller hearing, a mandatory proceeding during which the judge will decide whether a life sentence without the possibility of parole is appropriate for the teen who murdered four students and injured six students and a teacher in the shooting at Oxford High School in Oxford Township, Michigan. The expected duration of the hearing is two to three days.

Lt. Timothy Willis, the hearing's first witness, stated that a 22-page journal was discovered in a restroom stall, presumably left by Crumbley before he emerged from the hallway at Oxford High School and began firing.

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Will Ethan Crumbley Serve Life in Prison?

During the hearing, a five-minute surveillance video depicting the horrific shooting was presented in court as distraught family members of the victims watched. However, per the judge's orders, the media did not broadcast or photograph the video. In October, Crumbley withdrew his defense of insanity and pleaded guilty to 24 offenses, including first-degree murder, attempted murder, and terrorism.

Since the US Supreme Court ruled in 2012 that juveniles must be treated differently than adults, teenagers convicted of first-degree murder in Michigan rarely receive life without parole. A juvenile will only be sentenced to life in prison if he or she is deemed incorrigible, irredeemable, and has no reasonable chance of rehabilitation, according to Margaret Raben, former president of a statewide association of defense attorneys.

Per Daily Mail, Judge Rowe has set aside at least two days for the hearing, but a decision is not expected immediately. The attorneys for Crumbley will contend that he should be released at some point, claiming that the teen's untreated mental illness and "abhorrent family life" culminated in the violent act.

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