Michigan school shooter Ethan Crumbley has recently exhibited "sporadic disturbing behavior" in jail, prosecutors have said.
In a court filing Thursday, Oakland County prosecutors disclosed incidents of the recent behavior.
"Recently, Defendant has started exhibiting sporadic, disturbing behavior. This behavior has been documented via report and bodyworn cameras from jail personnel responding to various incidents. It is not readily apparent what the impetus for or cause is of this behavior," the filing says.
The filing states that the court is required to consider the behavior and Crumbley's ability to participate in future hearings saying, "These incidents relate to the defendant's competence."
A prosecutor called the behavior concerning Friday morning at a routine hearing evaluating Crumbley's detention in an adult detention facility as a minor.
Still, the prosecutor and Crumbley's defense team told the judge they believe the teen is competent to participate in his upcoming Miller hearing and sentencing.
The attorneys at the hearing said they are fully prepared to hold Crumbley's Miller hearing scheduled for July 27 during which prosecutors will present evidence as to why the teen should be sentenced to the harshest punishment in the state -- life imprisonment without the possibility of parole. His defense team is expected to argue mitigating factors in favor of a prison term of years.
Oakland County Circuit Court Judge Kwame Rowe deferred to the defense team that declined to refer him for a forensic evaluation and potential treatment at the Friday hearing.
Crumbley appeared via video during the remote hearing and spoke only to confirm that he could hear Judge Rowe and consented to the virtual proceeding over an in-person court appearance.
Crumbley pleaded guilty to fatally shooting four students and wounding seven others at his high school on November 30, 2021.
Crumbley entered the plea last October pleading guilty to one count of terrorism causing death, four counts of first-degree murder and 19 other charges stemming from the mass shooting at Oxford High School.
Prosecutors also noted in the court filing that Crumbley's recent behavior should not call his guilty plea into question.
"To be clear, the behavior referenced in this motion is recent and was not occurring at the time defendant entered his plea. There is no evidence that raises a bona fide doubt as to Defendant's competence at that time," a footnote in the filing says.
CNN reached out to an attorney for Crumbley for comment about the behavior.
The Oakland County Prosecutor's Office declined to comment further on the matter and records detailing the jail incidents were not immediately available.
"Due to restrictions on the release of healthcare-related information, our office will not comment beyond the information included in the brief filed yesterday and referenced in court this morning, " Oakland County Chief Assistant Prosecutor David Williams said in a statement to CNN.