I live in California and have loaned someone $1000.00. They signed a paper stating they would pay it back and have not yet done so and it seems as if they have no intent on doing so. Is this considered GRAND THEFT and if not what would it be called?
Thanks!

Its called defaulting on a loan and, no, its not theft of any kind. Unless you can prove he borrowed the money with no intent to repay. You take him to small claims court and sue him for the amount owed under the terms of the loan document.