Parents are divorced. Mother bought son a drum set 2 years ago for Christmas. Mother recently took out of state job and has kids 1/3 of the time (Dad has them 2/3 of the time). Mother stored son's drum set at a mutual friends house before she moved. Four months later, mutual friend asked father if he would like to take the drum set. Father did. Son wants drums at father's as son is at father's most of the time. Mother wants drums back. Says they are her personal property. Son is currently 15 years old. Will be 16 in March. Can father legally keep drums?