Obviously the Federal Government does not enforce the law, especially the law that is supposed to protect us. But, to bring the record up to date with regard to what they are obligated to do we simply present the law below. That is supposed to be all there is to it.
DEPRIVATION OF RIGHTS UNDER COLOR OF LAW
Section 242 of Title 18 of the U.S. Code makes it a crime for a person acting under color of any law to willfully deprive a person of a right or privilege protected by the Constitution or laws of the United States.
Read More at the Justice Department web site
U.S. law enforcement officers and other officials like judges, prosecutors, and security guards have been given tremendous power by local, state, and federal government agencies—authority they must have to enforce the law and ensure justice in our country. These powers include the authority to detain and arrest suspects, to search and seize property, to bring criminal charges, to make rulings in court, and to use deadly force in certain situations.
Preventing abuse of this authority, however, is equally necessary to the health of our nation's democracy. That's why it's a federal crime for anyone acting under "color of law" willfully to deprive or conspire to deprive a person of a right protected by the Constitution or U.S. law. "Color of law" simply means that the person is using authority given to him or her by a local, state, or federal government agency.
Read More at the FBI's web site
From Larry Becraft, Constitutional attorney:
State and fed grand juries are "controlled" by prosecutors who present cases to them. Prosecutors work with law enforcement and depend on cops and other agents for the cases they try in court, and friendships develop. After all, they are part of the same "team". Prosecutors are thus protective of most law enforcement agents... Prosecutors' attitudes and and objectives do play a substantial role in who gets indicted, and they certainly are "cop-friendly".