An emergency alert intended for just one area went across Ontario. Nobody will say how

"Emergency alert," the message appearing on phones read, warning people to shelter in place as police investigated a homicide. The suspect: "Unknown male."

As people were returning home from work and settling down for dinner last Thursday, phone screens in Toronto, Barrie, Peterborough and beyond lit up and let out an urgent sound.

“Emergency alert,” the message appearing on phones read, warning the public to shelter in place as police investigated a homicide. The suspect: “Unknown male.”

The order to shelter in place was only an instruction for residents in one Pickering, Ont., neighbourhood, local police later clarified. While the alert included an address and reference to Durham Region, it did not mention the town or neighbourhood in its text.

The emergency alarm was triggered by the fatal stabbing of an 83-year-old woman in a neighbourhood in the northwest of Pickering. It was a stabbing police said was random, eventually arresting a 14-year-old boy and charging him with first-degree murder.

None of that information was in the alert, which told people across the Greater Toronto Area and beyond to lock themselves inside.

“The area the alert extends to and what information is released is at the discretion of the OPP,” a spokesperson for Durham Regional Police, the force which requested the alert, told Global News.

“My understanding is the reach of the alert went further than the requested area as the armed suspect was mobile and there was an imminent threat to public safety.”

Global News Crime Analyst Hank Idsinga said while the area was large, it made sense to rely on the broad power of an emergency alert.