The condition of Hilal Bisan, a prison warden who was critically wounded Sunday after being shot by American-Israeli convict Samuel Sheinbein, has improved, hospital personnel have said.

Officials at Meir Medical Center in Kfar Saba reported that Bisan’s condition stabilized overnight, and he spoke with doctors before undergoing a final surgery to address light bleeding in his chest, according to Maariv.

The condition of another guard who had been seriously injured in the incident after being shot in the neck has also stabilized and his condition is now considered moderate, officials said. He was scheduled to be relocated to the spinal unit later Monday.

Sheinbein’s attorney, Orit Hayon, said Monday she believed more information was needed to understand her client’s behavior. In an interview with Army Radio, she said “I have known him for years. He was a good prisoner, and never caused problems during his furloughs from prison. The conditions granted to him would never have [been allowed] if he had not been behaving well.”

“He had no logical reason to commit these acts. Everyone is dealing with the question of how a gun was smuggled into the jail, but should really be addressing why no one communicated with him when he wanted to convey certain information,” she said, explaining, “He was in distress. I think someone threatened him and asked him to smuggle the weapon, but he didn’t have anyone to reach out to for help. I don’t think he intended to shoot those wardens.”

Hayon continued, “Why did they have to shoot and kill him when they possessed other means of neutralization? Why did they have to kill him?”

Hayon claimed that Sheinbein called her prior to the incident, and she could tell something was wrong. According to her, “We tried to warn the Israel Prison Service to look after him after after the conversation we had. We called the Rimon prison control center in order to seek help from the duty officer, but we never reached him. When we tried to get a hold of someone else we were told, ‘if his [Sheinbein's] life is in danger, he should pray to God.'”

Sheinbein, who was serving a life sentence for the 1997 murder of an acquaintance in Maryland, opened fire around 3 p.m. Sunday, injuring three guards before holing himself up in a cell. Two more officers who responded to the scene were also wounded in an ensuing shootout.

Two separate investigations, one by the Prison Service and another by the police, will attempt to answer a flurry of questions surrounding how Sheinbein acquired the weapon and managed to bring it into the tightly guarded prison, Israel Radio reported.

“It is utter neglectfulness that there is a pistol in a prison,” an unnamed Prison Service official was quoted by Ynet as saying. “It is neglectful that a convicted murderer prisoner to acquire a weapon, and it is even more neglectful that no one managed to discover the gun.”

An initial investigation revealed that Sheinbein had gone on furlough two weeks before the shooting and had arranged to purchase a gun from an arms dealer, Channel 10 reported. Sheinbein then attempted to rob the gun from the dealer, but was not successful. He was arrested by police, who immediately returned him to jail.

Since then, Sheinbein attended two more hearings regarding his case. Police suspect that while away from prison during those hearings, Sheinbein acquired a firearm and smuggled it into the jail.

Sheinbein was killed after barricading himself inside a cell for over an hour. After he shot at security forces, counterterror officers returned fire, critically injuring him, police spokesman Micky Rosenfeld said.

Times of Israel staff and AP contributed to this report.