how come my friend has not been charged yet?

The police raided my friends house a year ago. They found a half gram of meth. At the police station a cop asked him to become a CI, they released him and told him to think about it. a week later they came to him and he told them that he couldn''t be a CI. He has not heard anything since. the CI that the police used to get him was his cousin. He sold to her over a few months time, probably up to an ounce or two total. The cop at the station told him that it was a federal task force that raided his house. He''s worried that federal charges could still be coming. back ground on him . He was a small time dealer. he had been dealing for a few years to support his habit. worried for my friend.