A large cache of criminal case data belonging to the Dallas Police Department (DPD) is thought to have been lost forever.
About 22 terabytes of data went missing from the DPD computer database when data was migrated from an online, cloud-based archive to a server at the city's data center in April.
The data that disappeared included images, video, audio, case notes and other information gathered by police officers and detectives in relation to cases from before July 28, 2020.
Dallas PD attribute the data's permanent departure to the actions of a single city IT employee who it says "failed to follow proper, established procedures" while performing the data migration.
Authorities softened the announcement of the loss earlier this week with news that approximately 14 terabytes of data have since been recovered. The DPD believes the remaining eight terabytes of information are gone forever.
The quantity of information lost is considerable, since one terabyte can store as many as six million documents and 250,000 images.
District attorney John Creuzot said in a memo that it was "too soon to estimate how many cases will be affected and what the impact will be on those individual cases," but he was hopeful that duplicates of some of the data may have been stored elsewhere.
"It is possible that much of the missing evidence had already been uploaded to this office’s data portal prior to April 5," said Creuzot.
The absence of the case data was first noticed by city information technology officials on April 5. However, the Charlotte Observer reports that the district attorney's office was not notified of the loss until August 6.
This notification reportedly followed complaints from prosecutors who suddenly found themselves unable to locate computer files on pending cases.
"It is concerning that it took four months for the Dallas Police Department to inform the district attorney of the loss of the data," said Dallas defense attorney Amanda Branan, the president of the Dallas Criminal Defense Lawyers Association.
Dallas Mayor Eric Johnson is calling for the Dallas City Council to launch an investigation into the data loss.