The median response time for police officers was 152 minutes.
Some residents were from other countries and it will take time for police to receive information such as dental records.
President Barack Obama announced the findings of a White House task force into police practices and racial prejudice in police ranks and declared it was time for police departments across the country to take steps to rebuild trust with minority communities.
Belmar, the county police chief, said detectives still need to speak with several witnesses in the apartment complex near where Brown was shot, adding that it is taking time for police to talk to all of the witnesses.
These so-called "cracked trials", which cost more than £40m a year, are a huge waste of time for police, witnesses and victims.To offset these pressures, the government will have to come up with big incentives to persuade defendants to have their cases heard in the lower courts.
This is the time for police leaders throughout the world to challenge the status quo and focus resources on serious, organised criminals, not blighted users, and to focus on harm reduction not some pie-in-the-sky dream of a drug-free society.
Phil Gormley's decision to resign as Scotland's chief constable has brought to an end an extraordinarily unsettling time for Police Scotland but it will not, on its own, dispel the sense of crisis at the top of Scotland's national force.
Mr Rathband tweeted: "It's time for police to be armed in my opinion.
It could take some time for police to prepare the file for the PPS, with prosecutors then taking a further period to assess whatever evidence is presented.
But Ash Rathband, whose father David was shot and blinded by Newcastle gunman Raoul Moat, tweeted after the Hattersley incident: "It's time for police to be armed in my opinion.
