Hamilton police are urging people to be vigilant after a retired schoolteacher was slain in a "very savage attack" that has disturbed even veteran homicide investigators.

Police issued the warning at a press conference Friday because detectives believe 73-year-old Audrey Gleave was killed by a stranger or strangers who remain at large.

Without divulging too many details, Hamilton police Staff Sgt. Steve Hrab, who oversees the service's homicide unit, told reporters the city's 11th slaying of 2010 is one of the most horrific he's seen in the last decade.

"This crime here is particularly vicious ... I know they are all horrific but this is a retired schoolteacher living alone in her home who has been the victim of a horrendous crime," Hrab said.

Police said the attack may have been sexually-motivated.

Gleave was slain sometime this week before a friend found her body inside her home on Thursday morning. Gleave lived in a secluded farmhouse in the 3400 block of Indian Trail in Ancaster, just west of Hamilton.

Neighbour John Prenger said Gleave was retired school teacher from Hamilton's Westdale Secondary School who had a group of friends she would play golf with in the summer.

She and her husband moved to the neighbourhood 22 years ago. Prenger said he was not sure what happened to her husband, only that he hadn't been around for the past several years.

"She was living by herself and quite private," Prenger told CTV Toronto. "I don't think she was too involved in the actual neighbourhood. I've lived next to her for 20 years and I think I knew her better 20 years ago than I did the last couple of years."

Prenger said it was bizarre for something so tragic to happen in the quiet country community.

Ancaster residents Linda and Darryl Ferguson brought coffees to officers at the scene Friday afternoon, but were too distraught to say much about the tragedy in their quiet neighbourhood.

"I just hope the neighbours keep their doors locked and keep themselves safe. I hope whoever did thing gives themselves up," Linda told reporters.

An autopsy is being performed to confirm the cause of death, but Hrab said Gleave suffered multiple stab wounds and "other injuries" he didn't disclose.

He spoke to reporters while several officers were conducting a ground search for evidence around Gleave's property.

In addition to the warning, police are appealing to Gleave's friends, neighbours and anyone who's had contact with her recently to call investigators with that information so they can piece together her final days to narrow down the day and time of the homicide.

"The last time someone spoke to her was probably Monday evening, but we haven't confirmed that yet," Hrab said.

As well, police are asking people who saw anything or anyone suspicious in the area this week to contact them at 1-905-546-4067 or 1-905-546-4129, or Crime Stoppers anonymously at 1-905-522-TIPS (8477).