A gunman opened fire inside a motel room in the Phoenix suburb of Mesa on Wednesday, killing a man and wounding two women before shooting three more people as he sought to elude an exhaustive manhunt that ended in his capture, police said.

Officers using a stun gun subdued the suspected gunman at a vacant condominium where he had taken refuge, some four hours after the initial shooting, Mesa police spokesman Esteban Flores told reporters.

"At this time we believe he is responsible for each and every one of these shootings," Flores said. Police said the motive for the rampage was still unclear but that the initial gunfire erupted following an argument at the motel.