out on bond

What is the name of your state? iowa
If I paid to bond a person out of jail can I later turn him back in and get my bond money back? Sometimes it just doesn't seem like it was a very good risk and rather than take the chance of losing my money maybe he should sit and wait for his trial in jail.

It all depends on how you bonded the person out. If you paid a professional bondsman his fee to bond the person out, then no, those fees are generally not refundable.
But if you placed a cash amount as surety, with the court, then yes according to this Iowa statute.

811.8 Surrender of defendant.
1. At any time before the forfeiture of the undertaking, the surety may surrender the defendant, or the defendant may surrender, to the officer to whose custody the defendant was committed at the time of giving bail, and such officer shall detain the defendant as upon a commitment and must, upon such surrender and the receipt of a certified copy of the undertaking of bail, acknowledge the surrender by a certificate in writing.

2. Upon the filing of the undertaking and the certificate of the officer, or the certificate of the officer alone if money has been deposited instead of bail, the court or clerk shall immediately order return of the money deposited to the person who deposited the same, or order an exoneration of the surety.

3. For the purpose of surrendering the defendant, the surety, subject to the limitations of section 811.12 and chapter 80A, at any time may arrest the defendant, or, by a written authority endorsed on a certified copy of the undertaking, may empower any person of suitable age and discretion to do so. In making an arrest pursuant to this subsection, the surety or any person empowered by the surety shall possess no more authority than a peace officer would possess in making a lawful arrest under section 804.8, 804.13, 804.14, or 804.15.