Bratton to act as adviser on gangs and violence

“This is a prime minister who has a clear idea of what he wants to do,’’ Bratton said in a phone interview. “He sees this crisis as a way to bring change. The police force there can be a catalyst for that. I’m very optimistic.’’

More than 1,700 people have been arrested after a week of violence in London and other British cities that was triggered by a fatal police shooting under disputed circumstances. Police have been outmaneuvered by mobile gangs of rioters, and the unrest has stirred fears of heightened racial tensions.

Bratton, 63, said he believes British police need to focus on quelling racial tensions by collaborating more with community leaders and civil rights groups. He also said social media sites can be a useful tool for law enforcement trying to monitor gang activities.

“The idea is to get ahead of the violence rather than just react to it,’’ he said.

Another part of the potential long-term solution for London’s Metropolitan Police, widely known as Scotland Yard, is to become more racially diverse, Bratton said.

“Part of the issue going forward is how to make policing more attractive to a changing population,’’ he said.

Los Angeles and New York have benefited from police forces that “reflect the ethnic makeup of the cities,’’ he said.

Over the past two decades, Bratton has gained a reputation as a bold leader who refocused police departments in cities struggling with spikes in gang and other violence.

When Bratton stepped in as Boston’s police commissioner in 1991, the city was still being rocked by the violence that gripped many US cities in the late 1980s as potent and addictive crack cocaine flooded urban neighborhoods. The ensuing gang turf wars forced a dramatic spike in the city’s murder rate, hitting a high of 153 people in 1990.

Throughout the decade, Boston’s murder rate steadily fell to 35 in 1998. Soon top political figures, including President Clinton, hailed the “Boston Miracle,’’ with a good portion of the credit going to Bratton.

In 1993, Rudolph Giuliani, then mayor of New York, recruited Bratton to help him pursue his administration’s law-and-order agenda.