Thirty years ago, Pham allegedly shot six men in the back of the head while they were playing cards in a social club in Boston, Massachusetts.
RELATED: FBI warned of violent 'war' at Capitol in internal report issued day before deadly riot: Report
After what's known as the Boston Chinatown Massacre, Pham fled the country and was last seen in Bangkok, Thailand in the '90s, according to the FBI.
Just one man survived the massacre and the other five died.
"In addition to the quintuple homicide, Pham is also wanted by the Boston Police Department for another murder that occurred on January 8, 1991, four days before the massacre," the FBI said in a statement, which you can read here.
TIMELINE: A look back at the Golden State Killer's crime spree that lasted a decade
TIMELINE: A look back at the Golden State Killer's crime spree that lasted a decade
"Pham was an associate of the Ping On crime syndicate & has ties to Boston, Chicago, New York and Philadelphia," the FBI said on Twitter, adding, "He also has family in the San Francisco Bay area, Toronto, Canada, N. Vietnam and S. Korea."
The FBI says Pham should be considered armed and dangerous and an international flight risk.
He is 60 years old today, and the FBI says he may look like this:
The FBI says, "Anyone with information regarding his whereabouts should take no action themselves but should immediately call the FBI at 1-800-CALL-FBI (1-800-225-5324), their local law enforcement agency, or their nearest American embassy or consulate."
Tips can also be submitted here.