Story highlights The defense wants the Baltimore City State's Attorney's Office to be disqualified from the case

Six officers have been charged in Freddie Gray's death, all of whom have pleaded not guilty

Attorneys for the Gray family did not immediately respond to a request for comment

(CNN) Defense attorneys for the Baltimore police officers charged in Freddie Gray's death have filed more documents to support their request to disqualify the Baltimore City State's Attorney's Office from prosecuting the case.

Gray, a 25-year-old black man, died in police custody in April, sparking protests and riots in Baltimore. Six officers have been charged in his death, all of whom have pleaded not guilty.

In documents filed Thursday, the defense claims investigators from the Baltimore Police Department had information that Gray participated in "crash for cash" schemes, wherein he would intentionally injure himself to collect from insurance companies.

No proof was provided for that allegation. The document also claims Gray injured himself at the Baltimore City Detention Center so severely that he required medical attention. It was unclear when the alleged incident took place.

"When BPD investigators attempted to follow-up on this evidence of a pertinent character trait of Mr. Gray, they were told by Assistant State's Attorney Janice Bledsoe 'not do the defense attorneys' jobs for them' and to cease any further investigation into the matter," the filing read.

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