Police authorities in the small Californian town of Arroyo Grande have said an incident of cross burning is being investigated as a theft, arson and hate crime.

The police chief told CNN on Tuesday that his department is working with the FBI, the California Department of Justice, San Luis Obispo County District Attorney's investigators and the San Luis Obispo County Sheriff's Department to bring the culprit to justice.

The bizarre cross burning event took place outside the bedroom window of a black family after midnight on March 18. The 11-foot cross had been stolen from Saint John's Lutheran Church in Arroyo Grande, a small coastal town midway between Los Angeles and San Francisco. The hollow 100-pound cross was built eight years ago.

The violation was a shocker, according to the pastor of the church Randy Ouimette. You know, the cross originally was an instrument of violence. ... but Christ redeemed it. Through the cross has come forgiveness and peace.

The details of the black family near whose house the cross was burnt were not revealed by the police. But reports said a 19-yer-old woman in the family was distressed after the event.

There were allegations earlier that the local police initially dubbed the cross burning as a prank. But police chief Steven Annibali denied this and said his agency quickly acted on the case. Local authorities have announced a $3,500 reward in the case, besides putting in place campaign to raise reward amount.

Annibali, however, said he did not believe this was an act of any organized hate group. We feel right now that it's people who are local. We don't think it's an organized group or anything like that. It's bloggers who want to raise that issue, he told CNN. There's no active hate groups in Arroyo Grande, none that we're aware of...

Burning crosses, swastikas on synagogue walls, hateful words on mosque doors are not pranks. They are hate crimes meant to frighten and intimidate, 31 members of the San Luis Obispo Ministerial Association said in email sent to the San Luis Obispo Tribune.