Gilmore said his officers had training in February 2011 for dealing with an autistic person and had used Tasers in the past to subdue Watts on other occasions.

In Wednesday's incident, one of the officers who shot Watts did have a Taser, Gilmore said.

But Gilmore said his officers were in a situation where deadly force was needed, saying Watts had dictated the outcome by attacking the officer.

"He drew the line as to how the situation was to be handled," Gilmore said.

Gilmore said Watts had been taken in for psychiatric evaluations on several occasions.

"Regretfully this had to end in the death of a young man," Gilmore said.

Outside the police station at 1200 Pulaski Road, Watts' mother could be seen crying hysterically over the boy's death.

NBC 5 spoke to one of the boy's family members.

"They knew how he was," said the teen's uncle Wayne Watts, referring to the boy's autism. "They could have (used their Taser) on him."

Gilmore said the Illinois State Police are handling the death investigation, and the officers involved are on paid administrative leave.