Manhattan shooter had CTE: Medical examiner

(NewsNation) — The man who opened fire at an office building containing the NFL headquarters in Manhattan did have CTE, according to the Office of the Chief Medical Examiner of New York, reports say.

The determination confirms what Shane Tamura said in a note where he blamed the NFL for downplaying the risks of football and traumatic brain injury.

"Following a thorough assessment and extensive analysis by our neuropathology experts, OCME has found unambiguous diagnostic evidence of Chronic Traumatic Encephalopathy, also known as CTE, in the brain tissue of the decedent. The findings correspond with the classification of low-stage CTE, according to current consensus criteria," the office said in a statement.

Chronic Traumatic Encephalopathy (CTE) is a progressive disorder caused by repetitive head trauma. Symptoms of CTE include cognitive difficulty, trouble with movement, mood changes and behavioral changes, including increased aggression.

Athletes in contact sports like football and boxing have been found to have CTE, as have military members exposed to repeated explosions.

One of the challenges of understanding CTE is that it cannot be diagnosed until after death, when the person's brain can be examined.

Several former NFL players have been found to have CTE after their deaths, including Aaron Hernandez, who was convicted of murder.

Although he intended to shoot into the NFL offices, Tamura wound up on another floor of the office building where Blackstone was located.

Four people were killed in the shooting.

This is a developing story. Check back for more details.