On the eve of the commemoration of the Dec. 7 attack on Pearl Harbor by Japan 78 years ago, the Navy grappled with questions about Wednesday’s murder- suicide at the Pearl Harbor Naval Shipyard and another deadly shooting at Naval Air Station Pensacola in Florida.

Within a span of 23 seconds, a 22-year-old Navy sailor used two service weapons to fatally shoot two shipyard workers and injure a third before killing himself, officials said.

He had been undergoing counseling because he was unhappy with his commanders, a military official told The Associated Press on Friday. An official who spoke on condition of anonymity said the sailor faced nonjudicial punishment, a lower-level administrative process for minor misconduct.

Shipyard workers who spoke to the Honolulu Star-Advertiser but declined to be identified because they are not authorized to speak to the media said there have been multiple shooting suicides over the years at the shipyard and two within the past few months, but they could not recall a past murder.

A joint news conference held Friday just outside Pearl Harbor with military and civilian officials including Honolulu Police Chief Susan Ballard abruptly ended after brief statements and only two questions from the news media were allowed.

The officials did not answer questions on whether the gunman had been disciplined in the past or was facing disciplinary review and — if so — why he was allowed to be armed with an M4 rifle and an M9 pistol to guard the USS Columbia fast attack submarine.

Chuck Anthony, spokesman for Joint Base Pearl Harbor-Hickam, said officials were working on getting answers to a number of media questions, including confirming the number of suicides at the shipyard and specifically any violence associated with the submarine the sailor was supposed to have been guarding.

The Navy identified the shooter as Seaman Gabriel Antonio Romero of Texas but declined to provide his hometown. He was a machinist’s mate auxiliary fireman assigned to the USS Columbia, a submarine in Drydock 2 at the shipyard. On Wednesday he was assigned as watch-stander for the submarine.

There was no evidence of domestic terrorism, officials said at Friday’s news conference.

It appeared the attack by Romero was an isolated incident, that he acted alone and that it did not appear to have been motivated by any ideology, the FBI said.

No motive for the shootings has been determined, or whether the killer knew his victims.

Rear Adm. Robert Chadwick, commander of Navy Region Hawaii, said evidence was collected from Romero’s vehicle and barracks room.

Many of the details, including whether he was outside his assigned area, and what firearms he was authorized to have with him, remain undisclosed. Anthony said there is no general practice as far as watch-standers go. Some may have weapons; some may not, he said. He did not know how many sailors were assigned to guard the Columbia.

Romero, who enlisted in the Navy two years ago, killed himself at the scene, while the three civilians he shot were taken to hospitals. Two died and one survivor, 36, whom officials are not naming, remains in stable condition at The Queen’s Medical Center.

The two dead men were identified as Roldan A. Agustin of Hawaii, 49, a shop planner (nondestructive testing); and Vincent J. Kapoi Jr., 30, a metals inspector apprentice.

Agustin, a retired Hawaii Army National Guard staff sergeant, was deployed twice — once to Afghanistan and once to Kuwait — as an aviation maintenance specialist.

Brig. Gen. Kenneth Hara, Hawaii’s new adjutant general, shared what many in the Guard aviation community had told him about Agustin, saying he was “quiet, always in a good mood and a consummate professional who was very good at his job — so good that he took time off from the Hawaii Guard and worked as a contractor in Afghanistan.”

Agustin’s Facebook page says he had worked as a Department of Defense contractor at L3 Communications, lived in Ewa Beach and was from Waipahu.

He was born in Laoag City, Philippines, and moved to Hawaii when he was 2, his mother, Aida, said. “He’s a good man,” she told The Associated Press through tears, saying she was still shaking.

He enjoyed working on cars with friends and spending time with family, his brother said.

Kapoi’s family issued a statement saying he was an easygoing, fun-loving, “let’s do this” man “who will remain in our hearts.”

“There are so many unanswered questions and … it changes nothing. Because we can’t bring him back,” the statement said. “What we do have to do AND must do it, is honor his memory. Keep him alive in our hearts.”

He was married in April.

Kapoi’s services are scheduled for 3 p.m. Dec. 15 at Kamehameha Schools’ Kapalama Chapel.

GoFundMe pages have been set up for Kapoi under Angel of Hawai‘i at bit.ly/38gUb9C, and for Agustin at gofundme.com/roldanagustin.

Anthony told the Star-Advertiser that the alert system at Joint Base Pearl Harbor-Hickam did warn workers of an active shooter via text messaging to cellphones and computers as well as through loudspeakers called the “Giant Voice,” but there may have been a lag.

It is unclear whether the message was sent to everyone on base, which went into lockdown shortly after the shooting.

Civilian workers at the shipyard, which is a part of Joint Base Pearl Harbor- Hickam, said they are required to submit their cellphones before reporting for work.

On the other side of the country, the Florida shooter was identified Friday as Mohammed Saeed Alshamrani, a member of the Saudi military and an aviation student who fatally shot three people, injured several more and died in the attack.

The Associated Press contributed to this report.