Former CIA officer sentenced to 10 years in prison for spying for China

This part really stuck out to me

-> Two years later, Ma applied for a job as a contract linguist in the FBI’s Honolulu field office. By then, the Americans knew he was collaborating with Chinese intelligence officers, and they hired him in 2004 so they could keep an eye on his espionage activities.

-> Over the next six years, Ma regularly copied, photographed and stole classified documents, prosecutors said. He often took them on trips to China, returning with thousands of dollars in cash and expensive gifts, including a new set of golf clubs, prosecutors said.

So the government knew he was already working for a foreign agent, hired him at the FBI to keep tabs on him, yet he still stole classified documents during this time over 6 years?

Either this should be a huge intelligence blunder, or perhaps he was “stealing” innocuous information that the FBI allowed him to?

Also interesting they waited so long to arrest him. Wonder what was happening / being discussed that prevented it for so long.