The night Sean Bell was shot to death outside a Queens strip club last month, the spray of bullets was so wide that one shot punched through the glass of a sky tram station a block from the suspect's car. Of the 50 rounds fired, four wound up in Bell, killing the unarmed 23-year-old the night before his wedding.
In Atlanta, during a no-knock drug raid, police kicked in a door and killed 92-year-old Kathryn Johnson as the frightened grandmother met them with her revolver blazing.
In both cases, the police officers involved claimed probable cause and self-defense: Johnson opened fire first, and Bell could have been trying to ram the undercover officers with his car.
But in both cases, local communities are outraged at police.
"We have officers right now, that when they leave the police station, they don't know whether or not the community will embrace them now, because of what this has done to the department," said Atlanta Police Chief Richard J. Pennington.
Dr. Maki Haberfeld, chair of the Department of Law, Police Science, and Criminal Justice Administration at John Jay College, is a leading expert on police integrity. She said that while the majority of today's officers strive to protect and serve, many are paying for the brutality and corruption of a generation ago.
"It's still deep in people's minds, ingrained in people's minds that police are corrupt," Haberfeld said. "This country has a history of nine decades of police corruption. … In comparison to what we had for nine decades, police today are not corrupted."
Though the U.S. leads the western world in violent crime, an average police officer is armed and on the street after just 14 weeks of training. In contrast, Germany spends two-and-a-half years training a new recruit.
While many departments say they can't afford to train cops longer, some are trying to train them better. In Detroit, officers are now taught courtesy training, attend community meetings and man so-called storefront stations where everyday citizens are encouraged to help define the force.
"We bring them [the public] in on the ground floor," said Detroit Deputy Police Chief Jamie Fields. "The policies we develop affect the community, so we thought it best to bring them in on helping us develop the policy."
In Newark, N.J., where officers are feeling the ripple of resentment over the New York shooting nearby, newly-elected Mayor Cory Booker said crime will never ease until the "us versus them" mentality eases first, with cops and community giving each other the benefit of the doubt.
"You [have to] find a way to pull people together," Booker said. "You can't think that reducing crime is a law enforcement responsibility, or a government responsibility. It is all of our responsibility. If something goes wrong, it's not about finding blame. It's about accepting responsibility."
ABC News' Mark Reeves, Wendy Brundige, and Elizabeth Stuart contributed to this report.