More Protests Expected After Police Shooting of Black Man in North CarolinaLaw enforcement agencies in Charlotte, North Carolina, are bracing for the possibility of more street protests as they continue to investigate the fatal shooting of an African-American man by a black police officer. Protesters clashed with police and shut down a major highway Tuesday night and early Wednesday after Keith Lamont Scott, 43, was killed. He was shot by a plainclothes police officer who was looking for a criminal suspect in an apartment complex. The local police chief, Kerr Putney, said Scott got out of a car holding a gun. Scott's family strongly disputed the claim that he had a gun; they said he was holding a book when he was shot.  Police said they had video from the shooting scene but did not intend to release it to the public at this stage of the investigation. Reporters were told earlier that the officer who shot Scott felt that he was acting against "an imminent threat," and that a gun was recovered at the scene. The clashes overnight left about two dozen people injured, including 16 officers. Mayor Jennifer Roberts pledged officials would continue to be "thorough and transparent," but she also expressed concern that the protesters included "agitators" who live outside the Charlotte area.  The mayor said she was "calling for peace, calling for calm, calling for dialogue." Scott's daughter said he was reading a book in his car, waiting for the bus that drops off his son from school, when he was shot. She also said her father was disabled, and that police used a stun gun on him before shooting him four times. The police chief said her officers did not find a book at the scene. She also declined to identify the make and model of the gun police said they found near Scott's body.  Scott was one of an estimated 702 people who have been shot dead by law enforcement officers in the United States this year, according to the Washington Post, which said 163 of the victims were African-American men. Democratic presidential nominee Hillary Clinton addressed the issue of police shootings Wednesday at a campaign rally in Orlando, Florida. "We are safer when communities respect the police and when police respect the communities," Clinton said. She added that "too many people have lost their lives who shouldn't have," and "it's time to turn the tide, stop the violence [and] build the trust." WATCH: North Carolina Police Shooting Sparks Protest No media source currently available Protests in Charlotte began shortly after the shooting late Tuesday and extended into Wednesday. Police in riot gear tried to control the crowds and at one point used tear gas. Some demonstrators broke into trucks and stole cargo during a time when all traffic was halted on a major highway (Interstate 85) that runs through the city. Chants from protesters included the refrain "Hands up, don't shoot" — a phrase that has been repeated by demonstrators in many U.S. communities during the past two years where controversial shootings by police have occurred. Civil rights activists and ministers called for an economic boycott of Charlotte at a news conference Tuesday.  "We are calling on all black people in the city of Charlotte to keep your money in your pocket and let everybody feel the pain, economically, of what we are feeling physically when you kill us," Nation of Islam member B.J. Murphy said. This week's incident in North Carolina brought the Charlotte-Mecklenburg Police Department back into the national spotlight. Three years ago, a white officer was charged with manslaughter for shooting an unarmed African-American man; the case resulted in a mistrial, and the officer left the police force after reaching a financial agreement with the city. Another demonstration took place Tuesday outside police headquarters in Tulsa, Oklahoma, where a white officer killed an unarmed black man Friday. An attorney for the officer who killed Terence Crutcher said she feared for her life and fired when Crutcher reached through a window into his car. Crutcher's family disputed that account and called for action to be taken against the officer. The family noted that video released by police showed the window of Crutcher's car was closed; others have said the 40-year-old man was complying with police orders and placing his hands on the car to show he had no weapons at the time he was shot. Republican presidential candidate Donald Trump was asked about the Oklahoma shooting during a campaign appearance Wednesday in Ohio. He said Crutcher "looked like he did everything you're supposed to do [when stopped by police]. And he looked like a really good man." "This young officer, I don't know what she was thinking," Trump said. "I don't know what she was thinking, but I'm very, very troubled by that," calling the incident in Oklahoma "a terrible situation."  Crutcher's twin sister, Tiffany, said she was hopeful that something positive could come out of her brother's death. "We're hopeful that America will open their eyes — everybody — and see there's an issue, a systemic issue, that needs to be solved," she told a reporter for CNN television. "And we're pleading with the leadership of this country — everyone — just to see that. And let's put some systems in place to prevent this from happening again."