The Democratic nominee for president at the November election dismissed his opponent as incapable of tackling the violence himself.
“He doesn’t want to shed light, he wants to generate heat, and he’s stoking violence in our cities,” Mr Biden said during a campaign stop in Pittsburgh. “He can’t stop the violence because for years he’s fomented it.”
Mr Biden went on to denounce rioting, looting and arson at recent protests.
“It’s lawlessness, plain and simple. And those who do it should be prosecuted,” he said.
The speech marks a new phase of the campaign as Mr Biden steps up his travel after largely remaining near his home in Wilmington, Delaware, to prevent the spread of coronavirus.
And after centring his candidacy on Mr Trump’s mishandling of the pandemic, Mr Biden is making a broader push to argue that Americans will not be safe if Mr Trump wins re-election. That is an effort to blunt Mr Trump’s “law and order” message, which the president is emphasising as some protests against racial injustice have become violent.
A sense has taken hold in the Trump campaign that the more the national discourse is about anything other than the virus, the better it is for the president.
Mr Trump tweeted on Monday: “The Radical Left Mayors & Governors of Cities where this crazy violence is taking place have lost control of their ‘Movement.’ It wasn’t supposed to be like this, but the Anarchists & Agitators got carried away and don’t listen anymore – even forced Slow Joe out of basement!”
In Pittsburgh, Mr Biden said of Mr Trump: “He may believe mouthing the words law and order makes him strong, but his failure to call on his own supporters to stop acting as an armed militia in this country shows you how weak he is.”
Mr Biden is seeking to cast recent protests as the Trump administration’s problem. However, Mr Trump and Republicans are highlighting violence at protests as examples of what the country would look like under a Biden administration.
In Kenosha, Wisconsin, the National Guard was deployed to quell demonstrations in response to the police shooting of Jacob Blake, a black man, that have resulted in some looting, vandalism and the shooting deaths of two protesters.
And this weekend, one of Mr Trump’s supporters was shot at a demonstration in Portland, Oregon, prompting multiple tweets from Mr Trump himself, including one late on Sunday erroneously accusing Mr Biden of failing to criticise the “agitators” at the protests.
On Sunday, Mr Biden strongly denounced violent acts on any side.
“I condemn violence of every kind by anyone, whether on the left or the right. And I challenge Donald Trump to do the same,” he said in a statement.
Mr. President, it’s high time you condemn violence of any form. https://t.co/rQlXyadZid
— Joe Biden (@JoeBiden) August 31, 2020
Mr Biden said in Pittsburgh: “We are facing multiple crises – crises that, under Donald Trump, keep multiplying. Covid. Economic devastation. Unwarranted police violence. Emboldened white nationalists. A reckoning on race. Declining faith in a bright American future. The common thread? An incumbent president who makes things worse, not better.”
Portland has seen nearly 100 consecutive nights of Black Lives Matter protests, and many have ended with vandalism to federal and city property.
Mr Trump and other speakers at last week’s Republican National Convention frequently highlighted incidents of violence at protests that were sparked by the police killing of George Floyd last May, predicting that if Mr Biden is elected in November such incidents will become the norm.
However, Mr Biden accuses Mr Trump of viewing the violence as a “political benefit”.
“He’s rooting for more violence, not less. And it’s clear about that,” Mr Biden said last week.