Per ESPN's Adam Schefter, the NFL sent Brock an email announcing it found "insufficient evidence to support" him violating the league's personal conduct policy:
Brock was arrested on suspicion of felony domestic violence last April. He was accused of punching his girlfriend and attempting to strangle her when charges were formally brought against him two months later.
The charges against Brock were dropped in August when Santa Clara County prosecutors determined they didn't have sufficient evidence in the case after his girlfriend refused to cooperate in the investigation.
An eight-year NFL veteran, Brock was traded to the Vikings in September after spending the preseason with the Seattle Seahawks. The 29-year-old played seven seasons with the San Francisco 49ers, who released him in April following his arrest.