A mother is in critical condition and her son is dead after they were both shot during a home invasion in an upscale Philadelphia suburb over the weekend, officials said.

The mother and son were attacked in their home in Lower Merion Township at 2:20 a.m. Sunday, the Montgomery County District Attorney’s Office said.

The suspect is at large and has not been identified, an official in the district attorney’s office told ABC News.

Police are looking for information about a car and its driver, who they said fled from authorities in the area of the home invasion.

The victims’ 2004 Green Jeep Cherokee, which was stolen during the home invasion, was recovered on Sunday in West Philadelphia, the official with the district attorney’s office said.

It’s not clear if anything else was stolen from the home besides the Jeep, the official said.

A $5,000 reward is available for information leading to the killer’s arrest, authorities said.

ABC News’ Ben Stein contributed to this report.