Waterloo Regional Police now say they are looking for a red Honda Fit in connection with a murder in Cambridge on Wednesday, April 17.
Helen Schaller was shot that afternoon, on King Street East, near Church Street North and Westminster Drive North.
The 58-year-old was pronounced dead at hospital.
Police say the vehicle was spotted leaving the area at the time of the shooting and was heading towards Guelph.
Investigators are looking for information on anyone associated with the vehicle.
They also want to speak with a man, described as white, between 20 to 40 years, with a slim build and shaved or bald head.
Anyone who observes the vehicle, or man is asked to not approach, but to call 9-1-1 right away.
Police are also appealing to anyone who has information, or video surveillance, to call them at 519-570-9777 ext. 8666 or Crime Stoppers at 1-800-222-8477.
Meantime, a funeral for Schaller will be held on Wednesday morning.