TORONTO - Autopsy results have determined that an elderly couple found slain in their rural southwestern Ontario farmhouse earlier this week were shot to death.

The results indicate that William Regier, 72, and his wife Helene, 73, died between Sunday night and Monday afternoon in their home in Mount Carmel, north of London.

Police have set up a dedicated tip line as they continue their search for 22-year-old Jesse Imeson, the prime suspect in the couple's murder.

Imeson is also wanted in the death of Windsor bartender Carlos Rivera last week.

Imeson, who police considered to be armed and dangerous, is the subject of a Canada-wide arrest warrant.

Police say the search for Imeson has now spread to western Canada because he has lived in Whistler, B.C., and has ties in the Calgary area.

Imeson is also the top item on the website of the popular U.S. crime show "America's Most Wanted.''