In order to be convicted of Theft they have to be able to prove you had the intent to deprive them of the property. Given the facts you've laid out, what they would have to prove is that you were aware that your cousin was putting stuff in the car seat, with no intention of paying for it. If you paid for the items you picked out, and walked past the pay register with his items still hidden in the car seat, it's going to be a tough case. But, if you had no idea he had stuff hidden in there that he didn't intend to pay for, you may be able to get an acquittal.
Answered on Jan 21st, 2014 at 1:56 PM