SALEM – Three Lynn men and a Medford man who participated in the beating of a man at his Oakville Street home last year were placed on probation with conditions of community service and random drug tests.Courtney J. Gainey, 18, and his cousin, Anthony G. Gainey, 21, both of 65 Astor St., Lynn, with Bernard Edwards, Jr., 20, of 5 Elliot St., Medford, and Nathaniel J. Freeman, 19, of 86 Newhall St., Lynn, pleaded guilty Tuesday in Superior Court to a reduced charge of assault and battery in connection with the March 23, 2006 beating of Calvin Chaney.Courtney Gainey was placed on probation for a year and must complete 10 hours of community service.Anthony Gainey and Edwards were put on two years of probation and must each complete 25 hours of community service while Freeman was given three years of probation and 25 hours of community service.All four men must submit to random drug tests while being supervised, have a full-time job or be involved in an educational program and have no contact with a fifth accomplice, Brandon Payne.Assistant District Attorney Kristen R. Buxton said the group went to Chaney?s home at 91 Oakville St., and beat him with their hands by striking him in the head area and that “all” were involved in the act.Chaney, 19, who chose not to be present, sustained “significant injury and had to be hospitalized,” Buxton told Lowy.Authorities believe the incident was in retaliation for an earlier incident when Chaney apparently kicked out two of the suspects who reportedly were former roommates.Although the four individuals were also indicted on home invasion and an assault and battery with a dangerous weapon charges, the commonwealth agreed to drop them in exchange for their confessions.They were represented by Attorney?s Julie Buszuwski, Michael Phelan, Carmine P. Lepore, Jr., and Deborah McWade, respectively.Payne, 19, of Lynn, a cousin to the Gainey?s, pleaded to his role in the incident earlier and is now serving a 2 1/2-year jail term to be followed by probation.