That's Officer Daniel Pantaleo, laughing it up with one of his cohorts after just choking a guy to death..
Not a care in the world. This is what Sociopaths do. They have ZERO human empathy.
http://static1.nydailynews.com/polopoly_fs/1.1873239.1405826201!/img/httpImage/image.jpg_gen/derivatives/article_970/choke20n-16-web.jpg