Community activists who marched through downtown Denver to the state Capitol on March 27 say they have collected more than 1,000 signatures asking for a U.S. Department of Justice investigation into the Denver Police Department.

The march was organized by the Colorado Progressive Coalition, in part to memorialize slain Florida teenager Trayvon Martin but also to reiterate their desire for a federal civil-rights investigation in Denver.

Xochitl Hinojosa, a Department of Justice spokeswoman, said the department is reviewing the requests to investigate, but she declined to comment further.

Almost a year has passed since Thomas Perez, head of the DOJ's civil-rights division, said he was conducting a threshold review to determine whether his office needed to investigate Denver law enforcement.

At the time, the FBI was reviewing two cases involving the Denver police and sheriff departments — the April 2009 beating in Lower Downtown of Michael DeHerrera by a Denver police officer, and the July 2010 death of Marvin Booker, a homeless street preacher who died after an altercation with deputies in the jail.

"Three years after the beating of Michael DeHerrera and Shawn Johnson (a friend who was arrested) by Denver police officers, we have seen our community rise up together to say enough is enough," said Mu Son Chi, racial-justice and civil-rights director for the coalition. "While we have seen a new mayor, a new police chief and a new manager of safety, we have not seen systemic changes that would result in anything different if the same incident were to happen today. Today, our community is coming together in ways that are completely unprecedented."

The Colorado Progressive Coalition is still adding signatures to the petition, he said.

Denver police have said they can investigate and discipline their own officers, and an outside investigation is not warranted.

Felisa Cardona: 303-954-1219 or fcardona@denverpost.com