LYNN – The May death of a Lynn man who was found floating in Flax Pond has been ruled an accidental drowning, the Medical Examiner’s Office announced Wednesday.Richard Roussin, 20, of Maple Street, was found floating fully clothed in the pond on May 7.Roussin’s stepfather, Robert Hornsby Jr., declined to comment when reached by phone Wednesday, but said the family was aware of the medical examiner’s finding.In the days after Roussin’s body was discovered, police said investigators did not believe his death was caused by a swimming accident, nor were any signs of trauma found on his body.Hornsby said in May that Roussin was a graduate of Lynn Vocational Technical Institute and had been working for an electrician in the months before he died.A Lynn police spokesman was not available to comment on the case Wednesday evening.