Doody, 39, was also found guilty of burglary and conspiracy to commit armed robbery charges by the jury, the Arizona Republic, Phoenix, reported.
Sentencing was scheduled for March 14.
"Today's verdict confirms that the passage of time has not obscured the guilt of this defendant, nor has it diminished our commitment to seek justice for the nine innocent victims whose lives were senselessly taken," said Maricopa County Attorney Bill Montgomery.
"We now look forward to the imposition of an appropriate sentence that will hold him accountable for this horrible crime," Montgomery said.
Doody was charged with nine counts of murder and armed robbery, plus burglary and conspiracy to commit armed robbery, for the Aug. 10, 1991, massacre at Wat Promkunaram temple.
In 1994, he and co-defendant Alessandro "Alex" Garcia were sentenced to 100 years in prison each for the murders.
Garcia pleaded guilty to the charges, while Doody did not.
Doody's case was later thrown out by a federal appeals court because his alleged confession was improperly obtained by Maricopa County sheriff's deputies. Four other men were also cleared in the case.
In August, Doody was retried, but the judge tossed out the case after the jury reached an impasse. The third trial began in December.