Phoenix office complex shooting: Steve Singer and Mark Hummels killed, another wounded in shooting

PHOENIX - Two people were killed and another was wounded after a Wednesday attack at a Phoenix office complex.

Phoenix police Sgt. Tommy Thompson said 48-year-old Steve Singer died after he was shot by suspect Arthur Douglas Harmon.

Another victim, 43-year-old Mark Hummels, died Thursday night, his law firm told ABC15.

A third victim, 32-year-old Nichole Hampton, was shot in the hand and is expected to make a full recovery, according to police.

Phoenix police say 70-year-old Arthur Harmon fled the scene near 16th Street and Glendale Avenue after opening fire around 10:45 a.m. in the lobby of the law firm DeConcini McDonald Yetwin & Lacy, P.C.

Hummels was reportedly representing Singer in mediation at the time of the shooting.

Thompson said Harmon also shot at a vehicle on 16th Street after the shooting, when he learned he was being followed by a Good Samaritan. He remains on the loose as of Thursday morning.

Harmon fled in a white 2013 Kia Optima with Arizona license plate AVS-2052.

His body was found Thursday morning with a self-inflicted gunshot wound at Mesa Riverview near Loop 202 and Dobson Road.

SEE PHOTOS OF THE SHOOTING SCENE ON ABC15.COM

LAWSUIT MAY BE TIED TO SHOOTING. READ MORE ON ABC15.COM

Thompson said Harmon went into the law office for mediation Wednesday and apparently got into an altercation with Singer and Hummels.

Harmon then shot the victims and left the building, Thompson said.

Two other people police initially identified as "hurt" received treatment related to stress.

Phoenix police were later seen trying to locate Harmon at his home near 28th Street and Acoma Drive.

Police obtained a search warrant and moved in around 4 p.m. Two people were at the home but the suspect was not inside.

Officers were also called out to a Phoenix building near Central Avenue and Thomas Road around 1:15 p.m. after reports that a car at the location may be related to the shooting. It appears nothing was recovered at that location.

At the scene of the shooting, multiple police vehicles and fire trucks were parked in front of the office complex for several hours Wednesday.

Police officers and a police dog were seen sifting through the office building's parking lot, as tactical teams swept the building.

Harmon's body and vehicle were found Thursday morning by a landscaper near the Logan Roadhouse restaurant at Mesa Riverview, police said.