Marshall County officials believe they’ve solved the mystery of the death of a man whose body was found in a farm field. Investigators say a duo got spooked trying to steal anhydrous ammonia, and one of the guys ended up running over the other. 36-year-old Brian Eugene Ray of Tama was arrested yesterday for accidentally killing his companion in crime.Thirty-three-year-old Tommy Ray Phillips of Ferguson was found dead in the field earlier this week. Ray, the man arrested yesterday, is charged with reckless driving, vehicular homicide and conspiracy to manufacture meth.