The young boy was shot in the head as he sat in his Brampton, Ont., home on Wednesday night, watching TV. He died a short time later in hospital.
Police say the shot that killed the child "was not a stray bullet." They are working on the theory that the former residents of the home may have been the intended target.
The senseless act of violence has left the family "devastated," police say, while members of the community say they're worried.
Jennifer Millar grew up in the Brampton neighbourhood where the shooting happened. "We have lost too many kids because of these senseless acts," she said.
Illegal activity has become rampant, she said, with "drugs, and just young teenagers acting foolish."
A neighbour told CBC News there had been a lot of police at the home where Williams was shot — although that was before Kesean, his mother and his brother moved into the townhouse.
"There was a lot of cop activity," she said. "A lot of activity."
Neighbours suspect that before the Williams' family moved into the townhouse it was a haven for drug activity.
Peel Regional police have not made any arrests in the homicide, but say they have no reason to believe the nine-year-old, or his family, had any reason to live in fear.
By all accounts Kesean was a happy, friendly, Grade 4 student at nearby Winston Churchill Public School.
Grief counsellors have been at the school helping the children deal with Kesean's death.
But many parents say they will remain cautious until the crime is solved.
"A lot of people around here have kids," said another neighbour. "So it is really scary."