Son, 15, of Alton Sterling asks for unity

The 15-year-old son of a black man shot and killed by white Louisiana police officers says his father, Alton Sterling, was "a good man" and called for people to come together to deal with violence.

Protesters have been demonstrating against police brutality in Louisiana and across the country after Baton Rouge police fatally shot Alton Sterling, an African-American man, while he was pinned to the ground last Tuesday.

"The police didn't do their job in Baton Rouge, again", Marjorie Esman, executive director of the ACLU of Louisiana, said in a statement. The Justice Department has launched a federal investigation into the shooting, and the local prosecutor recused himself from any decision on criminal charges, citing his close professional relationship with the parents of one of the officers.

Police have said officers were called to the scene because of reports a man with a gun was threatening someone outside a convenience store.

Eight handguns were stolen from the pawn shop, six of which have been recovered, according to authorities.

But state and local law-enforcement authorities said the stolen guns were part of a credible threat to harm police officers.

"This is the reason", Dabadie said, "because we had credible threats against the lives of law enforcement in the city".

Baton Rouge Police Chief Carl Dabadie said the arrests help explain the recent show of police force against protesters.

Louisiana Chapter of the National Lawyers Guild President and Catholic nun Alison Renee McCrary: "I witnessed firsthand as peaceful protestors [sic] were violently attacked and arrested, assault weapons pointed at them with fingers on the triggers, some dragged across the cement, their clothes ripped off of them".

"[The police response] made me afraid to protest. If you don't have on riot gear, you have no defense against that sort of thing", the Democratic governor said.

"There is always a struggle with change, and there must be change in policing", Stewart said. The sheriff's department did not respond to a request for comment. "They're not out demonstrating and protesting simply just because it's something fun to do". But they have defended actions taken to keep demonstrators off a main artery in front of the police department and off the interstate. The killing has sparked nationwide protests against police using excessive force on minorities after graphic video of Sterling's death hit the Internet.

Cameron Sterling urged people to "come together as one united family".

D'Ahmad Winfield, 23, who is friends with one of the suspects, was detained and questioned by police.