The lawsuit on behalf of the family of Mary Delorenzo Knight was filed Wednesday morning.
A lawyer for the family said during a news conference that the navy and the contractors that employed Aaron Alexis ignored red flags about his deteriorating mental health.
Knight was one of 12 people gunned down by Alexis on Sept. 16 before he was killed in a shootout with police.
The lawyer also said that if the navy had a metal detector in place, Alexis would have never been able to bring a gun onto the property.
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