The Dallas Police Department is missing eight terabytes of data, much of which pertains to pending criminal cases, after hiccups in a system migration effort earlier in the year, the District Attorney’s Office announced on Wednesday.

On Aug. 6, the law enforcement body informed Dallas County District Attorney John Creuzot that in April the department discovered 22 terabytes were deleted over the course of a few days, according to a memo. A total of 14 terabytes has since been recovered, leaving eight terabytes still missing.