AUGUSTA ? Two days after losing guardianship of his grandson, a Great Bend man walked into an Augusta Wal-Mart Wednesday and fatally shot his son-in-law as he worked at the store, police said.

The suspect, who had guardianship of his daughter’s young son, had filed in court for full custody of the child. On Monday, a court awarded custody to the child’s mother and her husband.

“Apparently this really upset him,” said Augusta Department of Safety Chief David Pate.

The suspect’s 24-year-old son-in-law, who worked in the electronics department, was shot in the chest shortly after the store opened at 9 a.m. Aaron Matthew Ruboyianes, who was not the boy’s biological father, was pronounced dead at the scene. The gunman fired two or three shots, Pate said.

The identity of the suspect, who is in his early 40s, has not been released because he has not yet been charged in court. He was arrested on a charge of first-degree murder.

Ruboyianes’ wife, also a Wal-Mart employee, was in another area of the store when the shooting occurred.

“Of course, she heard everything, but did not know it was her father,” Pate said.

Her son, who police believe is 5 or 6 years old, was staying with his stepfather’s parents in Wichita at the time.

When police responded to the 911 call, a witness and another employee pointed out the suspect to officers. The man took off his jacket and removed a gun from his waistband before putting his arms in the air. He was arrested without incident, Pate said.

At least a dozen shoppers and eight employees were in the store at the time of the shooting, he said.