ELK GROVE, Calif. - Kamaljit Atwal's neighborhood seems like an unlikely place for a hate crime. His street in this Sacramento suburb seems a model of diversity.

Atwal and his family are one of two Sikh families on the block from India. On Atwal's street alone, there's a Vietnamese family, a Mexican family, a black woman and a white man.

But in March, Atwal's 78-year-old father Gurmej Atwal and his 67-year-old friend Surinder Singh were shot and killed while taking an afternoon stroll in the neighborhood.

Atwal and his fellow Sikhs in the area wonder if the same ugliness that has brought violence to other Sikhs is the reason why.

The men had long beards and were wearing turbans, both traditional symbols of their religion. Police are investigating whether their killing was a hate crime.

"It's a complete case of mistaken identity," said Rajdeep Singh of the Washington, DC-based Sikh Coalition, which is the largest Sikh civil rights group in the US "When people look at me with a turban and beard, the first thing that comes to mind is, 'That guy looks like Osama bin Laden.' "

Since the September 11, 2001, attacks, Sikhs have reported a rise in bias attacks, both verbal and physical, against them. The backlash that hit Muslims across the country has expanded to include them and their faith as well, with some assuming the sight of a long beard and turbaned head can only mean one thing.

Kamajit Atwal said life used to be peaceful for him, his wife and their three children since moving to his quiet suburban block in 2003. Crime has gone down for four years in a row, in Elk Grove, where about 54 percent of its 153,000 residents are nonwhite.

Atwal keeps a framed photo of his father on the fireplace mantel, not far from where the retired Indian civil servant once enjoyed his tea. Almost every day, Gurmej Atwal and his friend drank tea together, took a walk and met with other Sikh retirees in a nearby park.

"My gut is that it was a hate crime," said Atwal. He said that other elderly Sikhs are so afraid of being out in public since the shootings that they no longer socialize in the park.

Mayor Steve Detrick said he's not convinced the double shooting is a hate crime because the area has a history of accepting others.

"Elk Grove is probably one of the most accepting about racial and religious diversity in the country," he said. "I think somebody looked at these guys as an easy target. They were gunned down by cowards."

Amar Shergill, a Sikh and Sacramento attorney who lives in Elk Grove, said the problem is not Elk Grove's. When people - including some politicians - try to stigmatize all Muslims as anti-American, Shergill said, all people who look different are targeted unfairly.

"When the process becomes radicalized, that's when the disturbed actors take out on Sikhs and Muslims and people who are perceived to be Muslims," he said.

Singh said there's just not enough awareness of Sikhism, which is 500 years old and is the world's fifth largest religion with 18 million adherents. The faith, which originated in the Indian region of Punjab, draws from Hinduism and Islamic Sufism and the faithful believe in karmic cycles of rebirth, similar to Buddhists - and adherents stress that Sikhism is a distinct and separate religion.

Prior to 2001, Sikhs say, people were merely curious about the turbans and why adherents don't cut their hair. After September 11, some people felt that Sikhs were the enemy.

The Sikh Coalition said there have been at least 700 attacks or bias-related incidents against Sikhs since September 11 in the US.

Federal officials, however, have tracked hate crimes against Sikhs in one category, along with crimes against Muslims, Arab-Americans and South Asians - groups that have experienced discrimination since 2001.

In 2000, there were 28 anti-Islamic hate crime cases reported to the FBI, Department of Justice statistics show. A year later, there were 481. Since then, the numbers of reported cases have declined to 107 in 2009, the most recent year the statistics are available.

Sikh leaders sent a letter to US Attorney General Eric Holder in January asking him to track crimes against Sikhs separately.

Federal officials said Monday they are continuing to count Sikhs in the "anti-Islamic" hate crime category if the perpetrator indicated a bias toward Muslims.

The coalition will hold meetings in New York on July 30 and in San Francisco on August 27 so Sikhs can talk about bias and discrimination in the last decade. Videos of the meetings will be sent to lawmakers and police agencies. The coalition is also spearheading an effort this summer to stop bullying of Sikh children in schools after kids reported that other students tried to forcibly cut their hair, set their turbans on fire or attack them.

"Suddenly, our life has changed," said Rana Singh Sodhi, the brother of a man who was murdered outside of his Arizona gas station five days after September 11. "We didn't have any issue before 9/11."

Sodhi said that he and his family have stopped going camping in isolated areas because they fear what will happen.

The man who was convicted of killing Sodhi's brother expressed anger over September 11 and before the murder, had told his wife that "all Arabs should be shot."

In 2004, vandals scrawled the words "It's not your country" in blue spray paint on the wall of a Sikh temple in Fresno. No one has been arrested in that case.

In 2010, a Sikh cabdriver was beaten by two men in Sacramento - located in a region with more Sikh residents than any in the nation. During the attack, one of the men called the cab driver "Osama bin Laden," and the cab driver repeatedly told the assailants that he wasn't Muslim, authorities said. In early June, Pedro Ramirez was sentenced to 13 years in prison for the attack a second man was sentenced to a year in jail.

On Memorial Day of this year, four weeks after the US raid that killed Osama bin Laden, a Sikh man who is a subway employee in New York said he was punched in the mouth by a man who called him "the brother of Osama."

No one has been arrested.