Angry, a bully, a nut job - those are the words used to describe the man who opened fire at a Phoenix office complex Wednesday.
According to police, Arthur Harmon, 70, opened fire at the office complex, killing two men and injuring several others.
CBS 5 News spoke to a number of people who had contact with Harmon in the past.
Harmon was in the middle of a civil dispute stemming from some work he was hired to do for a Scottsdale company called Fusion Contact Centers.
Two of the victims in the shooting were Fusion CEO Steve Singer and his attorney Mark Hummels.
CBS 5 News obtained some letters Harmon had sent to Hummels last year, during the course of the litigation.
"You lying sack of s***," Harmon wrote. "Hummels, you're nothing but a sleazy lowlife attorney trying to ave your stinking skin."
"You (expletive), son-of-a b***. I am going after you with every fiber in my being and I wont rest until I see you behind bars for conspiracy to defraud," said Harmon.
Valley attorney David Panzarella said he saw firsthand how erratic and abusive Harmon could be.
"Having phone calls and dealing with him, you knew from the beginning he was different," Panzarella said. "Our office staff called him a 'nut job.'"
Several years ago, Panzarella represented a client in a lawsuit involving Harmon, who was representing himself.
Panzarella said that he remembers Harmon acting paranoid with obvious anger issues, whose main objective seemed to be dragging out the legal process.
Hearing what happened Thursday had an immediate impact on Panzarella's entire office, the attorney said.
"It was sobering to recognize that a guy like that, who files so many lawsuits and feels like he is put upon, was eventually going to snap somewhere," Panzarella said. "The fact he could have snapped at our office is frightening to think about."
CBS 5 News learned that Harmon was connected to at least five civil lawsuits since 1994.
In each case, Harmon represented himself.
Copyright 2013 CBS 5 (KPHO Broadcasting Corporation). All rights reserved.
Phoenix office shooter described as 'nut job'More>>
Police say a 1-year-old boy has died after being found unresponsive in a water-filled bathtub in Flint. The Flint Journal reports police are treating the child's death Monday night as suspicious. TheMore >
Police say a 1-year-old boy has died after being found unresponsive in a water-filled bathtub in Flint and now his parents have been charged in connection to his death.More >
Thursday, May 23 2013 5:49 AM EDT2013-05-23 09:49:05 GMT
A two-car crash between Bridgeport and Frankenmuth has resulted in the closure of Junction Road. The crash happened around 1 p.m. on Wednesday on Junction, between Reimer and Dixie Highway. BridgeportMore >
A two-car crash between Bridgeport and Frankenmuth resulted in the deaths of two people on Junction Road Wednesday afternoon.More >
Thursday, May 23 2013 12:09 AM EDT2013-05-23 04:09:41 GMT
An update now to a story TV5 first broke last week. State police have identified a second person who died in a Friday crash. 16-year old Brandon Anderson of Byron died this afternoon. A 16-year oldMore >
State police have identified a second person who died in a Friday crash.More >
Wednesday, May 22 2013 1:21 PM EDT2013-05-22 17:21:07 GMT
Police in Saginaw responded to the scene of a shooting overnight on the city's west side. The shooting happened just before 3 a.m. Wednesday off of North Woodbridge Street, between Hayes and Throop Streets.More >
Police in Saginaw responded to the scene of a shooting overnight on the city's west side and the victim has been identified.More >
Wednesday, May 22 2013 5:01 PM EDT2013-05-22 21:01:34 GMT
WNEM TV5 has learned the Michigan State Police bomb squad has been called to a pawn shop in Bay City. The Bay County Sheriff's department said someone was hoping to pawn the hand grenade but when staffMore >
WNEM TV5 has learned the Michigan State Police bomb squad has been called to a pawn shop in Bay City to check out a hand grenade.More >
Wednesday, May 22 2013 6:07 PM EDT2013-05-22 22:07:29 GMT
"I know I'm very fortunate to be alive, really. I just, I guess if I can help somebody then I will," said Mills."I can show them that there's life after amputation like people have shown me and repay theMore >
Staff Sgt. Travis Mills is back in Michigan for a visit -- on Thursday he will be the keynote speaker at a memorial service in Lansing.More >
Monday, May 20 2013 8:53 AM EDT2013-05-20 12:53:10 GMT
Michigan State Police are on the scene of a deadly accident. It happened just before five Friday evening at 10139 S. Sheridan in Genesee County's Gaines Township. MSP believes speed was a factor in theMore >
One teenager is dead and two others are in critical condition following a car crash Friday afternoon. It happened on the border of Shiawassee and Genesee Counties on County Line Rd, just south of Demond Rd around 4:30pm.More >
Wednesday, May 22 2013 11:58 PM EDT2013-05-23 03:58:05 GMT
New documents show why the state shut down a local day care.The Department of Human Services says the facility on Lauria Road in Bay County violated four rules.They include caregiver and child care homeMore >
New documents show why the state shut down a local daycare. The Department of Human Services says the facility on Lauria Road in Bay County violated four rules.More >
Friday, May 17 2013 7:16 PM EDT2013-05-17 23:16:53 GMT
One person has died in a crash near Harrisonville, MO, Thursday evening. The crash happened on Missouri Highway 7 and Walker Road. It involved a car and a tractor-trailer. Harrisonville is in Cass County.More >
Savannah Nash celebrated her 16th birthday last week. She died Thursday when her car slammed into a semi while she was texting during her first time driving by herself.More >