Law enforcement officials reportedly lack evidence that would tie a Booz Allen Hamilton contractor accused of stealing NSA hacking tools to an online leak of data in August.

Court documents say 51-year-old Harold Thomas Martin III, who goes by “Hal,” surreptitiously took “many terabytes” of data home from the National Security Agency over the course of his 16-year career in the intelligence community. The data is equivalent to millions of books, and reportedly contains information from the agency’s Tailored Access Operations division, or TAO, which is responsible for hacking foreign governments.