BOULDER, Colo. (AP/CBS4) – Protesters have called on the police department in Boulder to make sweeping changes after officers confronted a black man who was picking up trash in his yard. Hundreds of people marched Sunday to the Boulder Police Department, passing near the site where an officer detained 26-year-old Zayd Atkinson on March 1.

Zayd Atkinson (credit: CBS)

The Daily Camera reports the Naropa University student, who attended the march, says the officer had called for backup when he continued working in the yard.

(credit: Vanardo Merchant)

He says he believed he was going to be shot when an officer drew his gun.

(credit: CBS)

March organizer Nami Thompson and others called for the creation of a civilian oversight board to help prevent and mitigate conflicts with police.

“We’re here for reasons that should be unacceptable,” one protester told CBS4.

An image from Sunday’s march (credit: CBS)

(credit: CBS)

Boulder police are conducting an internal investigation into the confrontation.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)