The scream of the woman behind him let Daneel know that Alex was almost done chaining all of the guards, the leaders, and the servants, too, until it was proven that they didn't deserve it. It had been the thief's plan, all along, to let all these individuals who saw themselves as superiors be greeted with the same fate, and when Daneel had heard it, he had agreed that it was poetic justice, of a sort, which had definitely been coming for each and every one who had inflicted suffering in this town, thinking that there would never come a day when they would have to answer for their crimes.
Instead of using the adage of 'innocent, until proven guilty', they were using the opposite. Unless they heard from the slaves, themselves, that the people who weren't chained like them were innocent, Daneel would continue to presume that they were all guilty of crimes worthy of being killed for.