Criminal homework help

What would you do… 
While working a shift as security at a local mall you catch a shoplifter. The shoplifter seems to have disposed of the merchandise before you apprehended him. The merchandise adds up to $200 worth of electronics, including video games, CDs, and movies. Your client has asked you to sit down and interrogate the suspect to find out where the merchandise is. What approach would you use and why? How might body language help?