Disposal of a hunting rifle that has been used for suicide?

A friend of mine had a nephew that used a gun to kill himself several years ago. Its been in storage at his sisters house ever since, and the family wants to get rid of it. Of course practically, they could try and sell it, but because of the history they don't feel emotionally able to do that. Does anyone know of another option? We live in Utah, so I suppose there may be legalities involved. Any help is much appreciated.