CSI - New York 04 - Four Walls

Detectives Mac Taylor, Danny Messer, Sheldon Hawkes, and Don Flack are
called in to investigate a double homicide at a medium-security facility
on Staten Island. Racial tensions turned the prison into a pressure
cooker that finally boiled over in an all-too-lethal fashion, leaving
two inmates dead. One of the killings is an open-and-shut case, complete
with eyewitnesses; but the other, the murder of a former cop, defies
easy answers. Initial investigation of the crime scene
points to one cause of death, but the CSI team's scientific methods
uncover something completely different -- and wholly unexpected....

On the other edge of the city, Stella Bonasera and Lindsay Monroe look
into the murder of a young woman who worked at a popular Italian bakery