DENVER (CBS4)- The American Civil Liberties Union is calling for the Denver Police Department to ban pepper ball guns.

This comes after those pepper balls were used on Occupy Denver demonstrators in October 2011.

In one instance a man was shot out of a tree with ammunition and then pepper sprayed.

The ACLU is calling for Denver’s new police chief Robert White to get rid of the weapons.

“We’ve heard that with a new team in place things might change so this complaint provides a new opportunity for this new chief to show us they are prepared to take these allegations seriously,” said ACLU Legal Director Mark Silverstein.

The ACLU submitted a detailed complaint to White and the Independent Police Monitor asking for a formal investigation into what the organization calls “unreasonable and abusive use of force on Occupy Denver demonstrators.

The Denver Police Department said it had not received a copy of the complaint so they were not able to comment.

The Occupy Denver movement started in the weeks following Occupy Wall Street in Manhattan in the fall of 2011.