Cheating couple fatally shot while 'having sex in SUV'

Secret lovers killed in their car at an American park were having sex when they were shot multiple times in what police have called a "crime of passion".

Victims Shakoor Arline, 25, and Lisa Smith, 32, were both in relationships with other people, when they were shot in the head in Philadelphia, the New York Post reports.

At the time of the murder Arline and Smith were in the backseat of their SUV at Fairmount Park in an area sometimes referred to as “lovers’ lane”.

“You've got nine shots fired, all of them head shots to both of the victims, so it appears to be very much a crime of passion,” Homicide Captain James Clark of Philadelphia Police said.

It’s believed the killer opened the rear door of the vehicle and opened fire on the unsuspecting pair, who were partially clothed.

“So obviously that’s where our investigation is going to start, because somebody knew that they were in the park at that time and obviously had an issue with that,” Capt Clark said.

Reports indicate the shooting took place sometime between midnight and 5am Friday morning, with maintenance workers finding their bodies later in the afternoon.

Arline and Smith, believed to be a mother-of-five, had been seeing each other off and on after meeting at a previous job.

Authorities are yet to make any arrests over the murder.