PHOENIX (Reuters) - A man believed to be the suspect in a fatal Phoenix office shooting that killed one man and wounded a prominent Phoenix lawyer, has been found dead from an apparent self-inflicted gunshot wound, police said on Thursday.

Arthur Douglas Harmon, 70, was suspected of opening fire in an office building in central Phoenix on Wednesday following a legal mediation meeting, before fleeing in a car.

Phoenix police said officers in the Mesa suburb had located the suspect's Kia Optima sedan and "an individual matching the suspect description nearby with what appears to be a self-inflicted gunshot wound."

Harmon had opened fire following a morning meeting involving a legal dispute. Police identified the fatal victim as Steve Singer, 48. Law firm Osborn Maledon confirmed that litigator Mark Hummels - who is president of the Federal Bar Association's Phoenix chapter - was also wounded.

Police said the two men may have been the gunman's intended victims. A third victim, a woman, was not believed to have been intentionally targeted.

Hummels' practice focuses on business disputes, real estate litigation and legal malpractice defense, according to the firm's website.

News reports said the mediation session was over a lawsuit the suspect had filed against a call center based in Scottsdale, Arizona, although police were unable to confirm the report.

Television news images showed the suspect's white sedan parked in the lot of a Bass Pro store in Mesa, southeast of Phoenix. The car was ringed with crime scene tape, with police vehicles parked nearby.

The shooting came amid raised U.S. concern about gun violence after a gunman shot and killed 20 children and six adults at a Connecticut school last month, sparking a heated national debate over gun control.

It also coincided with the start of U.S. Senate Judiciary Committee hearings in Washington on possible gun control measures.

(Reporting by Tim Gaynor; Editing by Paul Thomasch, James Dalgleish and Andrew Hay)