Dozens march to federal prosecutor's office Wednesday.
The parents of a black teenager shot to death by a white New York City police officer in 2012 are demanding a federal civil rights probe.
The parents of Ramarley Graham led several dozen people in a short march from a park to the federal prosecutor's office Wednesday.
They submitted a letter demanding a full federal investigation, a grand jury probe and a meeting with the U.S. attorney.
A police officer was indicted on manslaughter charges over the Bronx shooting, but a judge tossed out the case, saying state prosecutors had improperly instructed grand jurors.
A second state grand jury decided not to indict the officer.
Last summer, a spokeswoman for federal prosecutors said federal authorities would review evidence to see if any civil rights laws were violated.