He was a Screaming Eagle of the Army’s legendary 101st Airborne Division. He deployed twice to Iraq and then landed a job at the Pentagon, working as an information technology specialist in the Joint Staff Support Center.

But on Tuesday, Staff Sgt. Ronald “Ronnie” Hamilton, 34, stepped into a Prince William County courtroom as a capital murder defendant, accused of fatally shooting his wife and a rookie police officer. If convicted, he could become Virginia’s fourth person on death row.

As prosecutors opened their long-awaited case against Hamilton, they described him to a jury of 14 women and two men as an unfaithful husband who shot his wife in their Woodbridge house multiple times, then killed a police officer on her first weekend shift — and nearly claimed the lives of two other responding officers. They portrayed him as a reckless father who committed the killings despite watching his wife desperately call 911 and in full view of their frightened son, Tyriq, then 11, fresh off his birthday and a sleepover.

“The man who presents himself as a protector in the uniform . . . was anything but,” Brian Boyle, a Prince William senior assistant commonwealth’s attorney, told the jury as he looked at Hamilton, dressed in a black military blazer with gold buttons and military honors.

Edward Ungvarsky, one of Hamilton’s attorneys, acknowledged in his opening statement that Hamilton fatally shot his wife and police officer Ashley Guindon, 29. But he said it was not premeditated. Hamilton, Ungvarsky told jurors, “lost it” during an emotional argument with his wife.

The shootings date back to the early evening of Feb. 27, 2016, when Hamilton and his wife, Crystal, a recovery care coordinator at Walter Reed National Military Medical Center, got into an argument at their rented two-story Colonial in Woodbridge. The couple’s marriage was falling apart — one of Hamilton’s attorneys said both were having affairs. They were staying in separate bedrooms, he in the master bedroom and she in the guest.

In court Tuesday, a statement written by Tyriq was read aloud by Crystal’s mother, Sherry Murphy of Wilmington, N.C. The boy, who is not testifying in the trial, described in his statement what happened in the moments right before his mother was killed.

“[My mother told him] he had no respect for her and then he said, ‘If you go out, you’re not coming back,’ ” according to Tyriq’s statement. The boy then went into his own bedroom. “I heard a loud noise. My mom came out and said he threw her against the wall, knocking the TV down.”

She then called 911, and prosecutors played the recording.

“What’s wrong?” the emergency call-taker asked.

“My husband just assaulted me,” Crystal said, crying and coughing, before saying Hamilton threw her up against the wall.

“My head. My head!” she said.

“What’s your name?”

“Crystal Hamilton. Stop!”

According to Tyriq’s statement, the boy said his father was ordering Crystal not to call 911. After Hamilton allegedly hurled his wife against a wall, the son said, his father came out and said, “Your mother is fine.”

And then, Hamilton went back into his wife’s room and closed the door.

“I heard, like, three shots, and then my mom went silent,” Tyriq said in his statement.

Eventually, Tyriq said, his father ordered him to leave the house. Tyriq said he was scared police might accidentally shoot him upon emerging from the home. He’d seen broken window glass bordering the front door and figured shots had been fired.

“I didn’t think they were going to, like, shoot me on purpose,” he wrote.

When he got outside their house, on the 13000 block of Lashmere Court, he saw three police officers lying on the ground and ran to safety. In the chaos engulfing their home, Hamilton had shot Guindon along with two other police officers, Jesse Hempen and David McKeown, veterans on the force, both in their 30s.

Shortly afterward, Hamilton gave himself up to authorities and admitted to the crimes.

The shooting prompted regionwide sympathy, particularly because Guindon, a former Marine reservist who grew up in New Hampshire, had just begun a new career as a Prince William police officer. The day before the shooting, the Prince William Police Department tweeted a photo of Guindon and another officer who had just been sworn in. “Be safe!” the tweet said.

It was the first time since 1990 that Prince William lost a police officer in the line of duty.

But prosecutors on Tuesday said Hamilton’s death toll could have been much higher.

Boyle, the senior assistant commonwealth’s attorney, said Hempen and McKeown nearly died from Hamilton’s gunshots. Boyle said McKeown suffered shots to his arm, chest, leg and groin.

“He can hear the blood pouring out of his body,” Boyle said, while Hempen had a “fist-sized hole” in his leg that threatened a key artery.

As for Guindon, at first, officials thought she’d be fine because they’d seen only one shot in her shoulder. But she kept complaining of shortness of breath. They checked for more wounds — and found another bullet in her back.

Ungvarsky said in his opening statement that Hamilton “couldn’t stand up to his fears” after his wife said she was going out with friends to a male entertainment club. When she insisted on her prerogative, he started assaulting her.

“Ronald Hamilton felt his world crashing down on him,” Ung­varsky said, adding that the man knew his actions meant the likely termination of his security clearance and military career, along with the separation of him and his child.

“He didn’t wake up with the idea of committing murder,” Ungvarsky said. Hamilton’s attorney also said he didn’t mean for police officers to get killed. He said Hamilton wasn’t even his aiming his weapon. After his arrest, he kept inquiring about the shot police officers.

“He cries. He cries,” Ungvarsky said. “He asked repeatedly about the health and well-being of the officers over and over again.”

An earlier version of this article incorrectly said there were five people currently on death row in Virginia. There are three.