FBI Profiler To Help in Possible New York City Serial Killings

Police said that no evidence has yet been recovered to indicate bias crime in Vahidipour's murder. Still, personnel from the NYPD Hate Crime Task Force were added Sunday to a group of detectives investigating the three homicides "for their expertise."

Former FBI agent and ABC News consultant Brad Garrett said the common thread between the three homicides could be that as shop owners working alone, they were all vulnerable.

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"The question clearly is motive. It's going to be robbery, hate, or revenge," Garrett said. "If the motive is robbery, a lot of violent robbers shoot the people they rob. If this is a hate crime, he went in there to do what he did, to kill the owner and have enough time to get away. If that's the case, I think it's reasonable to think all three of these guys were profiled previously."

Rewards of $22,000 in each of the homicides are being offered for information leading to the arrest and conviction of the person or persons responsible for the crimes.