ALBUQUERQUE, N.M. (AP) — A gunman storming through his former workplace fired without provocation or warning at his first victim, then moved on in a spree that left three dead and four injured, police said Tuesday.

A day after the shooting that ended with Robert Reza turning the gun on himself, Chief Ray Schultz detailed the 37-year-old's rampage at solar manufacturer Emcore Corp.'s Albuquerque plant. The shooting sent terrified employees scrambling, running to neighboring Kirtland Air Force Base or hiding behind locked doors and under desks, Schultz said.

A woman on a stairway outside an Emcore building was the first to be shot in the attack that police say capped a bitter custody dispute between Reza and his ex-girlfriend, Adrienne Basciano, 49, over their 5-year-old twins.

As he approached the building's courtyard, Reza twice shot Sharon Cunningham, 47. She died later at University of New Mexico Hospital.

Police said Basciano was shot several times and injured in an employee break area where she was sitting with another woman, 36-year-old Michele Turner. Schultz said Reza then killed Turner, shooting her multiple times as she lay helpless.

Three others were shot and wounded before Reza killed himself.

"We don't know if he saw those first responders and was unable to make an escape, but for some reason, while in that office, he took the handgun that he had and shot himself once in the head," Schultz said.

On Tuesday, University Hospital officials upgraded Basciano's condition from critical to serious.

Hospital spokesman Billy Sparks said two of the wounded workers, 54-year-old Malissia Mai and 58-year-old Rodney Noble, have been released. The other, 58-year-old Dixie Colvin, was in satisfactory condition.

Emcore's chief operating officer, Chris Larocca, said Tuesday that Reza worked for the company as a skilled laborer in the photovoltaic area between 2006 and July 2009. He went on medical leave in March 2009, returned to work that June, then resigned the next month.

Emergency dispatchers received more than 30 calls while Reza roamed the building.

After the shooting in the break area, Reza shot out a window, climbed into an office and went into a hallway, shooting at employees trying to get out of his way.

He fired in a foyer as employees tried to hide behind desks and hit Noble once in the back. Noble got out of the building on his own.

Reza continued shooting, hitting Colvin in both legs. Other employees got her out of the building and gave her first aid.

He then injured Mai, shooting her in the leg.

"It appears as he was going through the interior of the building, he was actually looking for something or someone," Schultz said, noting authorities may never know what Reza was looking for.

At one point, Reza went into a cafeteria where employees were but merely looked around before returning to the office where he'd entered the building, police said.

Reza then shot himself, Schultz said.

The gunman had fired 21 rounds, most of them outside.

Police recovered a .45-caliber semi-automatic handgun containing at least one round, plus additional ammunition. They also found a magazine to the gun outside, showing Reza reloaded before moving inside.

As officers searched, they found employees hiding and told them to stay put.

Schultz said Reza knew when his girlfriend might take a break.

"The fact that he went into the building after shooting her leads us to believe that he was actually in hunt for something or someone," the chief said.

The Emcore building was closed Tuesday but a stream of visitors dropped off flowers, candles and other items at a makeshift memorial.

Company officials said the plant will reopen Thursday. In the meantime, employees are on paid leave.

Larocca said Emcore is extending full salary and benefits to families of the victims for a year, paying funeral expenses and setting up a memorial fund.

Stella Baca, who has lived in suburban Rio Rancho across the street from Basciano for years, said she had not seen signs something like this would happen. Baca last saw the couple and their twins Sunday, a day before the shooting.

Basciano's brown stucco home sits in a quiet neighborhood, with towering yucca plants decorating a gravel yard. Police were at the home Monday night.

Baca said Reza, who moved out about a year ago, saw the children on weekends.

She called the shooting "unbelievable."

"A lot of people's lives were changed in a split second," she said.


Associated Press writer Susan Montoya Bryan contributed to this report.