The Lego art by Ai Weiwei cost $280,000. I spent $250 to create a forgery.

If it weren’t for the gallery assistant’s haughty, dismissive tone, I probably would never have stolen the painting.

To be clear, I’m not normally an art thief. My day jobs are as a civil rights lawyer and a law professor. Visual art is rarely my scene. So when my date invited me to see the Ai Weiwei exhibition in New York’s Chelsea neighborhood this past winter, I wasn’t exactly thrilled.

But walking into the Vito Schnabel Gallery, I was enthralled by the artist’s…