Republican nominee says his Democratic opponent ‘shares directly in with the responsibility for the unrest’ of protests against killing of black man in Charlotte

Donald Trump suggested on Thursday that Hillary Clinton bears responsibility for unrest that has followed police shootings of African Americans, saying she has “supported with a nod” the idea “that cops are a racist force to our society”.

Clinton “shares directly in with the responsibility for the unrest that is afflicting our country,” Trump told a crowd of several thousand in suburban Philadelphia, while the city of Charlotte, North Carolina, braced for a third night of protests following a fatal police shooting of a black man.

“Rioting in the streets is a threat to all peaceful citizens and it must be ended and it must be ended now,” Trump told the almost entirely white crowd. The Republican nominee dismissed a brief protest against him as the result of a few “violent disrupters” and pledged: “I am with you and I will fight for you” to “law-abiding African Americans”.

Trump’s remarks came as police confirmed the death of a protester shot in demonstrations in the aftermath of the killing of Keith Scott in Charlotte on Tuesday. Police and Scott’s family have given contradictory accounts of the shooting, with officers alleging he had a gun and family saying he held a book. After review of dashboard and body camera footage, the police chief and family both told reporters that video of the altercation is ambiguous. On Thursday night, however, protesters marched to the chant: “We want the tapes.”

On Thursday Oklahoma prosecutors also announced the indictment of a police officer over the fatal shooting of an unarmed African American in Tulsa, Oklahoma.

The Republican nominee suggested earlier in the day in Pittsburgh that protesters may have been acting under the influence of narcotics, telling the Shale Insight Convention: “If you’re not aware, drugs are a very, very big factor in what you’re watching on television.” Trump added that he would have “no compassion for lawless conduct”.

Mike Pence, the Republican vice-presidential nominee, also spoke about the issue on Thursday, telling pastors in Colorado that he disagreed with protesters who have demonstrated against police abuses for nearly two years. “Donald Trump and I believe that there’s been far too much talk of institutional bias or racism within law enforcement,” Pence said, insisting the issue was resolved. “We ought to set aside this talk about institutional racism and institutional bias.”

The Indiana governor added: “Police officers are human beings. In difficult and life-threatening situations, mistakes are made and people have to be held to strict account.”

The Republican nominee did not mention his proposal, first offered on Wednesday, to expand the controversial police tactic of stop and frisk. The tactic, which involved New York police officers stopping passersby, questioning them and checking for weapons, was found unconstitutional in 2013 because it disproportionately targeted African American and Latino people.

Earlier on Thursday Trump’s struggles with minorities were highlighted by the campaign’s county chair in Mahoning County, Ohio, who told the Guardian that there was no racism in the United States before Barack Obama became president – despite the country’s centuries of painful history with slavery, segregation, lynch mobs and systemic discrimination. The official, Kathy Miller, promptly resigned.

In contrast, Clinton did not hold any public events on Thursdaythough she spoke by phone with Jennifer Roberts, Charlotte’s mayor, as well as local congresswoman Alma Adams. Clinton has been preparing this week for the scheduled debate on Monday, which prompted Trump to mock: “They say she has been practicing for the debate, some people think she’s sleeping.”

Not far from several Philadelphia-area colleges, Trump also mentioned the problem of college affordability – and received an uncomfortable introduction from Indiana college basketball coach Bobby Knight, who praised Joe Paterno, a disgraced Penn State football coach.

“One of the people – one of the people that I admired most in college athletics was Joe Paterno,” Knight said. The former coach was fired in 2011 after revelations that he had known of sexual abuse allegations against an assistant coach, Jerry Sandusky, and did nothing for decades. Paterno died in 2012 aged 85, and remains a controversial figure at best in Pennsylvania. Sandusky was later found guilty on 45 counts of sexual abuse and is serving a minimum 30-yearprison sentence.