From FBI website at http://www.fbi.gov/hq/cid/civilrights/color.htm

It is a crime for one or more persons acting under color of law willfully to deprive or conspire to deprive another person of any right protected by the Constitution or laws of the United States.

"Color of law" simply means that the person doing the act is using power given to him or her by a governmental agency (local, state or federal). 

Criminal acts under color of law include acts not only done by local, state, or federal officials within the bounds or limits of their lawful authority, but also acts done beyond the bounds of their lawful authority. Off-duty conduct may also be covered under color of law, if the perpetrator asserted their official status in some manner. 

Color of law may include public officials who are not law enforcement officers, for example, judges and prosecutors, as well as, in some circumstances, non governmental employees who are asserting state authority, such as private security guards. 

While the federal authority to investigate color of law type violations extends to any official acting under "color of law", the vast majority of the allegations are against the law enforcement community. 

The average number of all federal civil rights cases initiated by the FBI from 1997 -2000 was 3513. Of those cases initiated, about 73% were allegations of color of law violations. Within the color of law allegations, about 82% were allegations of abuse of force with violence (59% of the total number of civil rights cases initiated).

The Supreme Court has had to interpret the United States Constitution to construct law regulating the actions of those in the law enforcement community. Enforcement of these provisions does not require that any racial, religious, or other discriminatory motive existed.
 

  Investigative Areas                          

Most of the FBI's color of law investigations would fall into five broad areas:

• excessive force; 
• sexual assaults; 
• false arrest/fabrication of evidence; 
• deprivation of property; and 
• failure to keep from harm.

In making arrests, maintaining order, and defending life, law enforcement officers are allowed to utilize whatever force is "reasonably" necessary. The breath and scope of the use of force is vast. The spectrum begins with the physical presence of the official through the utilization of deadly force. While some types of force used by law enforcement may be violent by their very nature, they may be considered "reasonable," based upon the circumstances. However, violations of federal law occur where it can be shown that the force used was willfully "unreasonable" or "excessive" against individuals.

Sexual assaults by officials acting under "color of law" could happen in a variety of venues. They could occur in court scenarios, jails, and/or traffic stops to name just a few of the settings where an official might use their position of authority to coerce another individual into sexual compliance. The compliance is generally gained because of a threat of an official action against the other if they do not comply.

The Fourth Amendment of the United States Constitution guarantees the right against unreasonable searches or seizures. A law enforcement official using his authority provided under the "color of law" is allowed to stop individuals and even if necessary to search them and retain their property under certain circumstances. It is in the abuse of that discretionary power that a violation of a person's civil rights might occur. An unlawful detention or an illegal confiscation of property would be examples of such an abuse of power.

An official would violate the color of law statute by fabricating evidence against or conducting a false arrest of an individual. That person's rights of due process and unreasonable seizure have been violated. In the case of deprivation of property, the official would violate the color of law statute by unlawfully obtaining or maintaining the property of another. In that case, the official has overstepped or misapplied his authority.

The Fourteenth Amendment secures the right to due process and the Eighth Amendment also prohibits the use of cruel and unusual punishment. In an arrest or detention context, these rights would prohibit the use of force amounting to punishment (summary judgment). The idea being that a person accused of a crime is to be allowed the opportunity to have a trial and not be subjected to punishment without having been afforded the opportunity of the legal process.

The public entrusts its law enforcement officials with protecting the community. If it is shown that an official willfully failed to keep an individual from harm that official could be in violation of the color of law statute.

  Filing a Complaint                         

In order to file a complaint alleging a violation of the criminal laws discussed above, you may contact your local FBI office by telephone, in writing, or in person. The following information should be provided:

• all identifying information for the victim(s); 
• as much identifying information as possible for the subject(s), including position, rank, and agency employed; 
• date and time of incident; 
• location and time of incident; 
• names, addresses, and telephone numbers of any witness(es); 
• a complete chronology of events; and
• any report numbers and charges with respect to the incident. 

You may also contact the United States Attorney's Office in your district, or send a written complaint to:

Criminal Section
Civil Rights Division
U.S. Department of Justice
P.O. Box 66018
Washington, D.C. 20035-6018 

Investigations vary in length and although there are internal limitations, the investigation will proceed to its logical conclusion. The FBI is the investigative component of the Department of Justice. It is, therefore, not responsible for the prosecution of a case. That is the responsibility of the Department of Justice, Washington, D.C., and the United States Attorney's Office within the local jurisdiction. After the FBI has completed its investigation, it forwards its findings to the United States Attorney's Office and to the Department of Justice. They then make the determination as to whether to proceed toward prosecution or not.

  Civil Applications                       

Title 42, U.S.C., Section 14141, makes it unlawful for state or local law enforcement agencies to allow officers to engage in a pattern or practice of conduct that deprives persons of rights protected by the Constitution or laws of the United States. This law is commonly referred to as the Police Misconduct Statute. This law gives DOJ the authority to seek civil remedies in cases where it is determined that law enforcement agencies have policies or practices which foster a pattern of misconduct by employees. This action is directed against an agency, not against individual officers. The types of issues which may initiate a Pattern and Practice investigation include:

Lack of supervision/monitoring of officers' actions. 
Officers not providing justification or reporting incidents involving the use of force. 
Lack of, or improper training of officers. 
A department having a citizen complaint process which treats complainants as adversaries. 

Under Title 42, U.S.C., Section 1997, DOJ has the ability to initiate civil actions against mental hospitals, retardation facilities, jails, prisons, nursing homes, and juvenile detention facilities, when there are allegations of systemic derivations of the constitutional rights of institutionalized persons.

Also see Department of Justice 8-1.000 CIVIL RIGHTS DIVISION