Many are asking how Aaron Alexis was able to get into the Navy Yard in Washington, D.C. on Monday and go on a shooting rampage, killing 12 people.
Channel 4 reached out to a labor law expert who gave some insight on hiring practices and background checks for new employees.
"For example, with respect to mental illness, employers can ask certain questions only at certain phases," said Labor and Employment lawyer, Vanessa Hodgerson.
Hodgerson spent the first part of her career in human resources and now represents companies as a labor lawyer for Fowler, White Boggs.
Hodgerson said in Alexis' case, a background check during the hiring process should have screened for his mental health issues.
"Employers can ask, 'Hey, do you have any issues related to mental illness or other medical inquiry,' but it's gotta be job-related and consistent with business necessity," said Hodgerson. "In other words, the employer has to have a reason to ask the question and tie it back to something that has to do with the job."
Background checks can offer some protection to employers, but Hodgerson said even using a criminal past as a hiring factor can be delicate work.
Hodgerson said that not even the government gets a free pass on the mental health issue.
"I always tell clients, I'd rather defend you in a lawsuit by EEOC, where they think you asked an improper question, as opposed to dealing with aftermath of unfortunate circumstances of yesterday," said Hodgerson.