Watch CSI: New York Help Season 5, Episode 12

After the leader of El Puno, a powerful New York gang, is killed, Mac (Gary Sinise) and the CSIs must find the killer before a street war with a rival gang erupts. To that end, Mac seeks help from the gang's co-founder (guest star Edward James Olmos), whom he put behind bars several years earlier, in the new episode "Sangre Por Sangre." Yancey Arias also guest stars.