article_snippet.sent: Police on horseback were helping to control Hundreds of protestors and at least one person was detained - an activist who jumped past police barriers - as protesters filled a street the length of a city block.
article_snippet.sent: Three Baltimore Police Department officers stand behind a barrier while protestors gather nearby .
article_snippet.sent: Bystander video of the arrest shows officers on bicycles, in patrol cars and outside the transport van.
article_snippet.sent: About 100 people had gathered around the start of the rally.
article_snippet.sent: NYC organized a rally Saturday night at the Baltimore Police Department's Western District police station .