The father of a man heading to trial for murder has been charged with two counts of attempted murder after a couple was threatened with a gun on the driveway of a house in northwest Calgary on Monday.

Police laid 11 charges against Keith Harkes, 64, including two counts of attempted murder.

His son, Mitchell Harkes, is awaiting a new trial after his second-degree murder conviction was recently overturned by the Alberta Court of Appeal. 

The son is accused in the stabbing death of Brett Wiese, 20, who died at a Brentwood house party in January 2013. A new trial has not yet been scheduled.

Investigators say the incident on Monday was domestic in nature. 

Around 6 p.m., a man and a woman had just arrived at a home in the 1200 block of Ranchview Road N.W. when another vehicle pulled up, police said in a release.

A man got out and walked toward the victims, pointing a firearm at them.

"At this point, it is alleged that the suspect attempted to fire the weapon, but that it malfunctioned," city police said.

The victims got back in their vehicle, backed out of the driveway and fled in reverse down the street as the man again pointed the gun at them, police say.

The man with the gun then got back in his vehicle and took off.

Later in the evening, the suspect went to the District 7 police station, where he was arrested.

Keith Harkes is charged with two counts of attempted murder, two counts of criminal harassment and seven firearms-related offences.