(CNN) Gary Martin made no secret of his intentions when he showed up for work at Henry Pratt Co. in Aurora, Illinois, on February 15, according to authorities.

He even told one employee, "If I get fired, I'm going to kill every mother*****r in here" and "I am going to blow police up."

But the employee did not report the comments because he believed that Martin "was always making 'off the wall' statements," according to an official review of the shooting dated April 26.

The employee was not named in the review.

Martin, 45, carried through with his threats that very day, fatally shooting five people and injuring six more, five of whom were police officers. He was killed in a shootout at the plant with police.

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