ANDREW DeMILLO, Associated Press

LITTLE ROCK, Ark. (AP) — Attorney General Eric Holder says the unrest after a police officer in Missouri fatally shot an unarmed black man in August shows law enforcement can’t let tensions with the community go unresolved.

Holder told a group of mayors and police chiefs that the shooting of Michael Brown by white Ferguson police officer Darren Wilson and the protests that followed show the need for expanded collaboration among law enforcement and the communities they serve.

Holder, who announced his resignation last month, spoke in Little Rock at the start of a two-day meeting by the U.S. Conference of Mayors. The meeting is focusing on lessons from Ferguson.

Former President Bill Clinton later told the group the Ferguson unrest highlighted the value of community-oriented policing initiatives he signed into law two decades ago.