Fresh protests were held across the United States as anger persisted over a grand jury's decision not to charge a white police officer in the fatal shooting of an unarmed black teenager.
In Ferguson, Missouri, scene of rioting after the November 24 ruling, the state governor said that more than 2,200 National Guard troops were now patrolling the streets of the St. Louis suburb.
Reports said one police car was torched and St. Louis County Police Chief John Belmar said 44 people were arrested during the second night of protest, but the situation was far calmer than the night before.
Thousands of people marched for a second night in New York City, while hundreds of protesters converged outside City Hall in Los Angeles, some throwing traffic cones and other objects at police officers in a three-hour standoff.
In Oakland, California, and Atlanta, Georgia, protesters blocked traffic and minor damage to local businesses was reported.
Protests were held in several other cities including Washington, Minneapolis, and Portland, Oregon.
Meanwhile, the officer who shot 18-year-old Michael Brown to death after an altercation on August 9 broke a long silence and said his conscience is clear.
Darren Wilson, 28, told ABC News that he felt he could not have done anything differently in the confrontation with Brown on a street in Ferguson, a mostly black suburb of St. Louis in which most police and other officials are white.
Wilson claimed Brown attacked him and tried to take his gun after a verbal altercation in which Brown and a friend refused to move from the middle of the street onto a sidewalk.
Wilson said he warned Brown he would shoot and opened fire when it appeared Brown was coming at him. Some witnesses said Brown had his hands up or was too incapacitated by a gunshot to present a threat when Wilson fired the final shots.
Anthony Gray, an attorney for the Brown family, and activists are questioning the hearing process especially how the prosecution presented evidence to the grand jury.
Gray said prosecutors withheld key evidence that might have supported the contention that police officer Wilson resorted to excessive force in trying to subdue Brown and that the killing was therefore unnecessary and illegal.
In comments on November 25, U.S. President Barack Obama condemned the violence in Ferguson, saying "destructive" actions were criminal.
Brown's death has reignited a nationwide debate and highlighted long-standing tensions over race relations, police tactics, and the use of firearms.