Dec. 4th, 1969: Police murder four Black Panthers including Fred Hampton and Mark Clark

"...Upon arrival, they were met by O'Neal, who had prepared a late dinner which was eaten by the group around midnight. O'Neal had slipped the powerful barbiturate sleep agent, secobarbitol into a drink that was consumed by Hampton during the dinner in order to sedate Hampton so that he would not awaken during the subsequent raid. O'Neal left at this point, and, at about 1:30 a.m., Hampton fell asleep in mid-sentence talking to his mother on the telephone.[9][10][11][12] Although Hampton was not known to take drugs, Cook County chemist Eleanor Berman would report that she ran two separate tests which each showed a powerful barbiturate had been introduced into Hampton's blood. An FBI chemist would later fail to find similar traces, but Berman stood by her findings.[13]

Body of Fred Hampton, after being shot twice in the head at point blank range by members of the Chicago Police Department.

The raid was organized by the office of Cook County State's Attorney Edward Hanrahanusing officers attached to his office.[14] Hanrahan had recently been the subject of a large amount of public criticism by Hampton, who had made speeches about how Hanrahan's talk about a "war on gangs" was really rhetoric used to enable him to carry out a "war on black youth".[15]

At 4:00 a.m., the heavily armed police team arrived at the site, dividing into two teams, eight for the front of the building and six for the rear. At 4:45, they stormed in the apartment.

Mark Clark, sitting in the front room of the apartment with a shotgun in his lap, was on security duty. He was killed instantly, firing off a single round which was later determined to be a reflexive reaction in his death convulsions after being shot by the raiding team; this was the only shot the Panthers fired.[4][16][17]

Automatic gunfire then converged at the head of the bedroom where Hampton slept, unable to wake up as a result of the barbiturates that the FBI infiltrator had slipped into his drink..."

http://en.wikipedia.org/wiki/Fred_Hampton