A German tourist remains in a Calgary hospital in critical condition after he was shot in the head while driving on a rural highway and now Cochrane RCMP have seized a car matching the description of a vehicle of interest in the case.

Cochrane RCMP located and seized a black four-door Chrysler Sebring, found on a residential street in the community and secured it for forensic examination.

An adult male who lives at a nearby home was also detained but his involvement in the incident that resulted in a German tourist being shot in the head is still under investigation.

The man and his family were travelling in a Dodge Durango in the westbound lane of Highway 1A, near Morley, just before noon when they heard a banging noise.

The driver, a man in his 60s, lost control of the vehicle after he was shot in the head through the window.

"In the driver's side window, there was a bullet that penetrated from the exterior and became lodged in his brain," said Sergeant Tom Kalis with the Cochrane RCMP.

When first responders arrived at the scene, the man was conscious and breathing and he was taken to Foothills Hospital where he remains in critical condition.

"The victim did undergo surgery last night," said Sgt. Kalis on Friday. "He pulled through the surgery, but might have some lasting, permanent effects as a result of the trauma."

There were three others in the vehicle who sustained minor injuries.

Police say the shot came from a passing vehicle and originally thought that it was a case of road rage, but are now backing off from that theory, saying that information strongly suggests otherwise.

RCMP say that none of the occupants of the Durango were the intended targets of the shooting.

Investigators say a small, black sedan was seen in the area at the time and they are looking to speak to a male who was in the vehicle. He is described as being Caucasian with long dark hair.

A man in an R.V. that was driving on Highway 1A saw the SUV crash and called 911.

RCMP say the R.V. stopped but left the area soon after and they are now asking the driver to contact the Cochrane detachment.

Officials say it was an isolated incident and that there is no risk to the public.

Police are asking anyone with information to call Cochrane RCMP at 403-851-8000.

(With files from The Canadian Press)