Nikolas Cruz's Brother: Body Cam Footage Shows Arrest at Stoneman Douglas

Zachary Cruz, the younger brother of Florida shooter Nikolas Cruz, is seen on video -- obtained by TMZ -- outside the very school where Nikolas slaughtered 17 people.

Zachary was arrested for trespassing, this after he's caught on tape telling officers he was there to "take it all in." That was enough for cops to take his backpack and search for possible weapons.

The video shows a calm, mild-mannered 18-year-old wearing nondescript clothes -- a white t-shirt, baseball cap and headphones. Cops say he had been skateboarding on the grounds of Stoneman Douglas High School.

It seems cops were, at first, willing to let Cruz go with just a warning, but as other officers arrived it became clear he was on the property several times before and was warned to stay away. That's when police had a change of heart and decided to cuff him and take him in.