Robert Olson said he wanted to watch one last sunrise, then be shot dead by the dozens of Gilbert and Mesa police officers that responded to the Gilbert wastewater treatment plant where he worked.

The orange dot painted on his white shirt and gauze wrapped around his head marked his preferred targets for SWAT officers, Olson told investigators, according to a newly released 111-page police report.

A look back: Suspect wanted big explosion, police say

Instead, Olson surrendered peacefully to police, who were held at bay in armored vehicles April 1 at the Greenfield Water Reclamation Plant, which was venting volatile methane gas after Olson manually shut it down.

The gas, Olson told police, was his "fail safe" to ensure a gunshot or other weapon would ignite the gas after the sun came up over the plant at 4400 S. Greenfield Road. The plant is owned by Gilbert, Mesa and Queen Creek. It's operated by the Mesa Water Resources Department, and Olson was an operator at the plant.

Olson said he realized an explosion could hurt "a lot of people," the report said.

Olson is scheduled for a hearing June 3 in Maricopa County Superior Court, where he has pleaded not guilty to felony charges of terrorism, first-degree burglary, criminal damage to property and misconduct involving weapons.

In interviews with Gilbert police after his arrest, Olson spoke of a growing resentment against Mesa and his supervisors, whom he considered taking hostage in an effort to get better working hours and force his supervisors to be removed or retired, the report states.

His growing frustration with the city was fueled by a mental disorder that had spawned dual personalities, which were being treated with medication, the report said.

"Olson feels a suppressed angry aggressive individual personality coming forward and taking over another personality," an officer wrote, noting Olson posted a message on Facebook "that stated he had embraced the evil side, he liked it, and felt so empowered."

Pressure had been building since Olson, his wife of 20 years and their two children lost their home to foreclosure two years ago and then filed bankruptcy. The family had moved in with Olson's in-laws.

On his way into work March 31, Olson stopped at a Walmart, where he bought some light beer, bottles of Mike's Hard Margarita drinks and beef jerky.

At 11 p.m., Olson arrived at the plant and relieved Rod Liebe. Liebe didn't report anything out of the ordinary when Olson arrived, according to the report.

About midnight, Olson disabled a system that would notify plant operators of any problems. Then, over the next 57 minutes, Olson turned off wastewater pumps, digesters and flares that burn off increased methane gas, the report states.

"Besides backing up the system, this caused this building's basement floor to flood with approximately a foot and a half of raw sewage," police reports state. "Due to these pump and valve manipulations, methane gas was exhausted (vented) into the atmosphere for approximately 4� hours at a normal rate of between 80 and 120 cubic feet per minute."

Plant supervisor Ray Aguallo and city officials have repeatedly said the gas posed no serious threat of exploding, but Aguallo told Gilbert police "it was conceivable that some type of an explosion would occur if the methane was ignited."

Olson grabbed a folding chair and retired to atop the Solids Building, where he watched a DVD and washed down 15 Xanax and 15 Concerta pills with three beers and three margaritas.

About 2:30 a.m.,Olson called 911 and told a dispatcher he had taken the plant hostage, that methane was building up, and he was armed with a knife and handgun.

"Olson wanted to see one last sunrise come up and the methane gas being vented was his fail safe," the report states. Olson "wanted to 'commit suicide by cop.' "

Gilbert SWAT officers and Mesa police began negotiating for his surrender, which Olson did about two hours later.

Olson "believed his actions were justified because the city of Mesa management needed to know that the employees have power," the report states.

Olson stated he was angered that employees have repeatedly gone without pay raises while city leaders agreed to spend millions to keep the Cubs from relocating from Mesa to Florida.

Olson remains in jail on $250,000 bond.