Business Law needs to be done immediately

In the following situations, two parties claim the same goods.  Who is most likely to prevail in each circumstance and be sure to explain why.

(a) Charlie steals David's Ultra HD TV and sells it to Eddie, an innocent purchaser, for value.  David learns that Eddie has the tv set and demands its return.

(b)  Gail takes her all terrain vehicle (ATV) for repair to Henry's Sales & Repair, a merchant who fixes and sometimes sells used ATVs.  By accident, one of Henry's employees sells Gail's ATV to John, an innocent purchaser and customer, who takes possession.  Gail wants her ATV back from John.