Armstrong was convicted in 1995 for the 1988 murder of a one of his former professors. According to WRAL:
A key prosecution witness said police pressured him to accuse Armstrong. A re-tested palm print from the murder scene belonged to another suspect who was later convicted of killing his father and died in a 2010 traffic accident. No fingerprints or other physical evidence at the murder scene pointed to Armstrong, a former teacher and car salesman who was arrested repeatedly after he started using heroin. Police and prosecutors also kept other evidence from defense attorneys, including information about a neighbor who said she saw another man in Compton's neighborhood around the time of the killing wearing bloody Army fatigues, according to a court filing on Armstrong's behalf by the Duke Wrongful Conviction Clinic.See story here.