US Attorney General Eric Holder sought to reassure the people of Ferguson about the inquiry into the shooting death of a black 18-year-old by a white police officer.
The attorney general remembered how he was stopped twice on a New Jersey highway and accused of speeding. Police searched his car, going through the boot and looking under the seats.
"I remember how humiliating that was and how angry I was and the impact it had on me," Mr Holder said during a private meeting with about 50 community leaders at St Louis Community College.
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"I will work with him where we can, but I just didn't want to go celebrate or legitimise or normalise his presidency," one US lawmaker said.