HONOLULU (AP) — The Navy said Tuesday its investigation into a shooting at Pearl Harbor last December was unable to determine what caused a submarine sailor to fire his service weapon at three civilian workers, killing two and wounding one, before he fatally shot himself.

But the Navy’s investigative report said 22-year-old Gabriel Romero had “several stressors” in his life in the months leading up to the shooting that together “likely led him to choose violence.”

Further, the report said the U.S. Pacific Fleet submarine force’s mental health program failed to properly diagnose Romero’s mental health condition during eight visits he made to a clinic between September and November 2019.

Still, U.S. Pacific Fleet Commander Adm. John Aquilino said no one could have predicted Romero would “engage in this ultimate act of murder and suicide” even if his mental health issues and his grievances had been known.

“This lack of