Lorenzo Lamas' Son A.J. -- Meth Pipe Found During Target Arrest

It's become a lot clearer why Lorenzo Lamas' son A.J. allegedly stole random items from Target ... we've learned he was carrying a meth pipe during the incident.

TMZ broke the story -- A.J. was arrested last month after he allegedly tried walking out of a Target store in Van Nuys with a wrench, clothes and tennis shoes. Cops said A.J. made a getaway after punching a security guard while holding a baby in his arms. He was apprehended at a nearby hotel.

Now we're told A.J. will have to deal with charges of theft, battery, child endangerment, and possession of drug paraphernalia ... all misdemeanors. He's pled not guilty to the charges.

We reached out to a rep for A.J. So far, no word back.