A lawyer wounded by a gunman in a Phoenix office shooting this week has died, the second of three people hit by gunfire in the attack, the publicist for his law firm said Friday.

Mark Hummels, 43, had been on life support at a Phoenix hospital after Wednesday morning's shooting that killed a company's chief executive and left a woman with non-life threatening injuries.

Colleagues of Hummels described him as a smart, competent and decent man who was a rising star in his profession and dedicated to his wife, 9-year-old daughter and 7-year-old son.

The gunman — Arthur Douglas Harmon, 70 — was found dead early Thursday in the Phoenix suburb of Mesa from an apparent self-inflicted gunshot wound, police said.

Harmon opened fire at the end of a mediation session at a north-central Phoenix office building over a lawsuit he filed last April.

Steve Singer, 48, a father of two and CEO of Scottsdale-based Fusion Contact Centers LLC, died hours after the shooting.

Harmon targeted Singer and Hummels and "it was not a random shooting," police said. A 32-year-old woman not involved in the mediation was caught in the gunfire near the building entrance and suffered a gunshot wound to her left hand.