NORTH MIAMI BEACH, Fla. - North Miami Beach police said surveillance video shows dozens of high school students demonstrating in the Trayvon Martin case Friday ransacking and shoplifting from a Walgreens store. The incident occurred during a walkout from North Miami Beach Senior High School in support of Martin, 17, who was fatally shot in Sanford. Protesters have been calling for the arrest of George Zimmerman, 28, who has not been charged because he claimed self-defense in the shooting, according to police. Minutes after walking out of their school Friday at about 11 a.m., a large group of students walked...