The father of slain teenager Michael Brown said Wednesday that he and his wife came to the United Nations "to get justice for our son." (Reuters)

The parents of Michael Brown, the man shot and killed by a Ferguson, Mo., police officer, took their case to the United Nations torture committee Tuesday.

In private testimony before the United Nations Committee Against Torture, they claimed the killing of their unarmed teenage son in August and the “excessive force by police officers on peaceful protesters” in Ferguson in the weeks that followed violated the principles of a U.N. convention.

Lesley McSpadden and Michael Brown Sr. traveled to Geneva and spoke before the committee, which works to protect human rights.

“We need the world to know what’s going on in Ferguson and we need justice,” McSpadden told CNN. “We need answers and we need action. And we have to bring it to the U.N. so they can expose it to the rest of the world, what’s going on in small-town Ferguson.”

In a prepared statement submitted with other advocates, Brown’s parents revisited Aug. 9, when white police officer Darren Wilson killed 18-year-old Brown. Accounts of the incident vary, but Brown’s parents focused on the events that followed. The statement was submitted by the Organization for Black Struggle, Hands Up United and Missourians Organizing for Reform and Empowerment.

Demonstrators confront police outside the Ferguson police station on Oct. 13. (Scott Olson/Getty Images)

“The intimidation caused by the shooting of Michael Brown and the disrespect for his body was amplified by the impunity that followed,” the statement said. “Officer Wilson has not been arrested, and public officials have shown a clear reluctance to actively pursue his prosecution.” It continued: “The most egregious acts of excessive force by law enforcement in Ferguson took place during the protests in the weeks following Brown’s murder, when law enforcement officials donned riot gear, tanks, armored vehicles and other military-style armaments, and placed the town under siege in response to largely peaceful protests.”

The statement urges the U.N. panel to recommend Wilson’s immediate arrest and Ferguson Police Chief Thomas Jackson’s resignation. In addition, it asks that the Ferguson Police Department be held accountable for “systematically targeting and harassing residents of color in a predatory and degrading manner” while granting amnesty to protesters arrested during demonstrations.

The statement recommends that the Department of Justice “conduct a nationwide investigation of systematic police brutality and harassment in black and brown communities, and youth in particular. Methodology and findings of this investigation must be made publicly available.”

Their plea comes as the nation awaits a grand jury decision on whether Wilson will be charged with a crime amid widespread concern about how Ferguson residents will respond if he isn’t.

“We don’t want anyone acting irrational or acting before thinking,” McFadden said. “Because it wouldn’t be serving us any purpose, it wouldn’t be doing us any good. We’re trying to get a message across.”