The Navy contractor identified as the alleged gunman in Monday's mass shootings had a number of mental health problems including paranoia, unnamed law enforcement officials told the Associated Press.
Aaron Alexis, the 34-year-old Navy veteran who died in Monday's shootout, was being treated for his mental health issues that also included hearing voices in his head and having sleep issues, family members told police.
Despite these issues, the Navy had not declared him mentally unfit, according to the AP.
While some friends reportedly expressed disbelief that Alexis could be the shooter, there's other evidence of mental instability in his past. In 2004, Alexis was arrested in Seattle for shooting the tires of another vehicle, according to the Seattle Police Department's Crime Blotter.
Alexis later told police he couldn't remember firing the weapon, and that he had a "blackout" fueled by anger. He was also arrested in Fort Worth in 2010 for discharging his weapon, according to that city's NBC affiliate.