Police say the child's mother has given them a statement about her involvement.
She and the boy's godmother were found drugged and unconscious near the boy.
Those who know the family say it is tragic end to a long and desperate search for help.
A video from the Autism Media Channel on YouTube shows Alex Spourdalakis in February during one of many hospitalizations. His mother can be seen tenderly washing Alex's feet.
"Dorothy, the mother, had absolutely nowhere to go, nowhere to live. With this boy, she would go from motel to motel," said Polly Tommey, Autism Media Channel.
Polly Tommey and her Autism Media Channel worked with Dorothy Spourdalakis - recording these public pleas for help.
"He needs something simple, in the country, where he can run around, get the treatment that he needs so he can get better," said Dorothy Spourdalakis, Alex's mother, in the YouTube video.
"She was crying and so was the godmother. They were both in a terrible state - that's why we did that plea in the hospital for help," said Tommey.
The help never came. Over the weekend, police went to an apartment above a River Grove plumbing company and Alex was found stabbed several times. His mom and godmother at his side, alive but unconcious. There was a three page letter describing the ordeal of caring for a severely autistic- and sometimes violent- teenager.
Polly Tommey feared the breaking point was near when she last spoke with Alex's mom.
"She didn't know what was going to happen, how it was going to end. She just kept saying this was the end of Alex," said Tommey.
Originally labeled a death investigation, police said on Tuesday they are pursuing this as a homicide. The weapon, which had been missing, was found, wiped clean, inside the home. And police say charges will likely be filed shortly.
According to River Grove police, it was about 3:00 p.m. on Sunday that they came to the second floor apartment to conduct a well-being check. Police said they were called to the scene after the boy's father and uncle failed to get in touch with him or his mother. Police found Alex Spourdalakis, 14, stabbed to death in bed.
Alex and his mother, Dorothy Spourdalakis, 50, lived in an apartment together over a plumbing business. River Grove police say his mother and another woman were incoherent and unresponsive by his side and under the influence of some kind of narcotic.