The Obama administration is providing senior state and local police officials with its analysis of homegrown terrorism incidents, including common signs law enforcement can use to identify violent extremists.

The warning signs identified for police include someone joining a group advocating violence, receiving support from a network that plans attacks or seeking out charismatic leaders who encourage violence. The analysis was conducted by the Homeland Security Department, the FBI and the National Counterterrorism Center. An overview of the findings was shared with The Associated Press.

The conference Wednesday at the White House marks the first time this unclassified analysis will be presented to 46 senior federal, state and local law enforcement officials, many of whom are police chiefs and sheriffs. The conference will also include sessions on other programs the federal government has for countering violent extremism and a briefing from a deputy chief of the Los Angeles Police Department about what the city has done on this front.

"Engaging local communities is critical to our nation's effort to counter violent extremism and violent crime, and this meeting brings together many of our partners," Homeland Security Secretary Janet Napolitano said. Napolitano, Attorney General Eric Holder and the president's counterterrorism adviser, John Brennan, planned to attend the White House conference.

There has been an uptick in attempted attacks by Americans and other legal U.S. residents in the past few years, prompting the Obama administration to place a priority on finding ways to stop this type of violence. The administration rolled out a thin strategy last year that put local communities — not Washington — in charge of countering violent extremism in the U.S. That strategy was short on details and did not focus on threats from Islamic extremists.

The White House has encouraged law enforcement to reach out to Muslim communities to build relationships, insisting that these communities are partners in the fight against terrorism. At the same time, the government is trying to develop ways to help local law enforcement detect behavior that could indicate someone is plotting a violent attack. The challenge has been to provide behavioral indicators that indicate the potential for violence rather than religious beliefs or other constitutionally-protected rights.

Analysts from the FBI, Homeland Security Department and National Counterterrorism Center reviewed 62 cases of homegrown violent extremists and found basic similarities. The cases included violent extremists who adhered to a mix of ideologies, including people who ascribed to white supremacist beliefs and people inspired by a violent interpretation of Islam. The analysis is not a psychological profile of a homegrown terrorist, but instead offers similarities among cases that could help local law enforcement better understand and detect threats.

In the 62 cases reviewed, the subjects increasingly spoke out against the government, blamed the government for perceived problems and did so in a way that caught the attention of other people in their communities, according to the senior counterterrorism official who spoke on condition of anonymity to discuss the private White House event. Subjects became active on the Internet to espouse extremist views. In some cases, the subjects purchased weapons, ammunition or explosive materials.

Analysts found that a person's origin, ethnic background and socioeconomic status are not good indicators for potential violent extremist activity, the senior counterterrorism official said.

Later this month, a training program for local law enforcement on countering violent extremism will be tested in Southern California, and the government intends to roll out the training to the rest of the country through 2012. Part of the training will focus on understanding constitutionally protected activities so law enforcement can distinguish between illegal acts and free speech. The official said the FBI academy plans to incorporate this training into its programs as well.

The FBI came under fire last year for some controversial training sessions that portrayed Islam as a violent religion.