Borrowing items from friends and family members often comes with a promise to return the borrowed item. Life happens and that promise might be broken at some point.
If you forget to return an item that you borrowed, you will likely return it as soon as you remember. If you don't remember to return it, the person from whom you borrowed it might accuse you of stealing. Proving that in court as a criminal matter might not be as easy as simply making an accusation.
When it comes to forgetting to return a borrowed item, a criminal charge is possible. A conviction on a theft charge in that circumstance is a different matter. A conviction on a theft charge requires that the prosecutor prove that you borrowed the item with the intent of never returning it.
It is necessary for the prosecutor to prove beyond a reasonable doubt that you didn't want the owner to have his or her property back. This is often difficult to prove. However, if the person repeatedly asked for his or her property to be returned and you failed to do so, that alone might prove intent.
In these cases, it is always critical that all evidence and information be considered before deciding on a defense strategy. In some cases, it might be possible to have the charges dropped. Still, you must ensure that you are building your defense until the case is actually dropped or goes to trial. The last thing you should do is show up to a trial unprepared because you wrongly assumed that everything would be dropped.
Source: FindLaw, "Can I Be Accused of Stealing Something I Borrowed If I Forget to Return It?," accessed Dec. 03, 2015