The activist minister and television host spoke at Manhattan's Riverside Church three days after the death of Eric Garner on a Staten Island street.
Garner was "choked by New York City policemen," the Harlem preacher told the congregation. "What bothers me is that the nation watches a man say 'I can't breathe' and the choking continues, and police surround him and none of them even say, 'Wait a minute, stop! He can't breathe!'"
"When does your sense of humanity kick in?" he asked.
The officer linked to what the police commissioner has said was an apparent chokehold has been stripped of his gun and badge and placed on desk duty.
Chokeholds are banned under department policy. Garner's cause of death has yet to be determined.
Court records show that within the past two years, three men sued Daniel Pantaleo the officer seen wrapping his arm around Garner's neck over allegedly unlawful, racially motivated arrests. Garner was black.
In the first lawsuit, settled by the city in January, two black men accused Pantaleo and other officers of arresting them without cause and subjecting them to a "humiliating and unlawful strip search" on the street in which they were ordered to "pull their pants and underwear down, squat and cough." The men said they were held overnight on charges that were ultimately dismissed.
In a second lawsuit, a man accused Pantaleo and other officers of misrepresenting facts in a police report and other documents to substantiate charges that also were dismissed.
The president of the city's largest police union called Pantaleo's reassignment an unwarranted, knee-jerk decision.
In addition to Pantaleo, an eight-year NYPD veteran, a second officer who has been with the department for four years was taken off the street but retained his gun and badge. The reassignments will remain in effect while prosecutors and internal affairs detectives probe Garner's death, police said.
However, Sharpton said it was equally wrong for a New Jersey man to fatally shoot an officer last week. His widow said he should have killed more officers but later apologized for the remark.
Whether police kill citizens or citizens attack police, "both sides are wrong," Sharpton said, drawing applause.
Video of Garner's struggle with police obtained by the New York Daily News shows the 6-foot-3, 350-pound man becoming irate and refusing to be handcuffed as officers tried to arrest him on suspicion of selling untaxed, loose cigarettes.
Garner, who has been arrested for illegally selling cigarettes numerous times in recent years, told the officers who confronted him Thursday that he had not done anything wrong, according to the video of the arrest.
"Every time you see me, you want to mess with me. I'm tired of it. It stops today," Garner shouts. "I'm minding my business. Please just leave me alone."
Then, as four officers bring him down to the sidewalk, Garner, who was asthmatic, gasps, "I can't breathe! I can't breathe!" The video shows one officer using his hands to push Garner's face into the sidewalk.
The 43-year-old father of six was declared dead shortly after at a hospital. Authorities believe he suffered a heart attack.
More tests are needed to determine the exact cause and manner of his death, a spokeswoman for the medical examiner's office said.
Garner's funeral is scheduled for Wednesday at the Bethel Baptist Church in Brooklyn.