The Huffington Post reported Sunday on the lawsuit, which accuses Justin Cosma, who was with the Jefferson County Sheriff's office at the time, and another officer of using "unreasonable and excessive" physical force against the boy. The accusations came in September 2012, just after Cosma joined the force in Ferguson.
The Huffington Post's Ryan Reilly, a former reporter for TPM, identified Cosma as one of the officers who arrested him and another journalist from the Washington Post last week at a Ferguson McDonald's amid heated protests.
Cosma and the other Jefferson County officer, Richard Carter, approached the boy in June 2010 and asked if he had been playing on nearby highway, according to the lawsuit. When the boy said that he hadn't, the lawsuit claims the officers "became confrontational."