He earned a bachelor's degree at Pace University in social science and youth agency administration. He became a corrections officer at Rikers Island after being beaten by two white police officers, and became a police officer himself in 1991.
In 1990, Davis started an organization called "Love Yourself" Stop the Violence dedicated to stopping violence in urban America. He became a minister, and then a New York City Councilmember for Brooklyn's 35th Council district, elected in November 2001.
The template for his successful City Council bid had been established by previous races against Assemblyman and Democratic Kings County Chair Clarence Norman Jr., who narrowly defeated him in 1998. The campaign caused the NYPD to fire him for being in violation of a rule that prohibited paid city employees from engaging in electoral politics. After pursuing litigation against the police department, Davis was vindicated and was allowed to return to his job.
His next campaign was successful but would later be a factor in Davis's murder. Othniel Askew had raised funds to run against him, but had failed to file the proper papers on time, which led to accusations of political chicanery and caused Askew to harbor a grudge against Davis.
On July 23, 2003, across the street from his alma mater, Davis brought Askew to attend a Council meeting at New York City's City Hall, with the intention of honoring him by introducing him from the balcony. The councilman and Askew were able to bypass the metal detectors, a courtesy offered to elected officials and their guests. At 2:08 p.m., Askew fired a silver .40 caliber weapon at Davis, striking him twice in the chest. Davis, a retired police officer, was carrying a weapon but it remained holstered. A plainclothes policeman, Richard Burt, on duty as bodyguard to Gifford Miller, Speaker of the City Council, then shot Askew, striking him five times. Paramedics arrived quickly, and attempted to revive both Davis and Askew before taking them to Beekman Downtown Hospital, but both died.
Askew had a history of violence. It was discovered after the murder that Askew had asked Davis to sign papers naming him as Davis's replacement in case anything happened to Davis.