Biden has not supported calls to defund the police, as Trump and Pence have claimed.
He has proposed reforms that will change the way law enforcement operates, but will not lead to chaos. For more on the reforms Biden will implement, see the argument 'Joe Biden will reform the police force and the criminal justice system'.
It is also wrong to attribute the unrest to Biden. As president, Trump must take responsibility for at least some of the violence, especially the brutality of law enforcement on protesters. Biden has accused Trump of "pouring fuel on the fire. He's encouraging this. He's not diminishing it at all. This is his America now".