Your friend is a loving idiot. He should have just admitted to the shoplifting in the first place. Most cops appreciate honesty and will most likely let him off the hook, maybe a fine at worst. But by lying he pissed the cop off. To make it even worse he ran, that turns from Petty shoplifting to felony evading, jail time. My advice would be that he just turns himself in now, because the cops will find him, and the longer he makes them wait, the more the jail time grows.
As much as I hate helping stupid punks like him, I have some tips for your friend that may help in court. You said after the lecture the cop searched him, did your friend consent to being searched, if so, disregard this. But if he didn't, the cop violated your friends privacy rights. The only way a cop is allowed to search someone without that persons consent is with a warrent, if he already arrested your friend before the search, or if he could visibly see something that breaks the law (A gun, drugs, or the pocket knife in your case). If the cop violated your friends rights, that could be a valuable asset.
