Northwest District police called to investigate a domestic incident in the city’s Forest Avenue-Grant Street area early today found anything but a domestic dispute.Instead, according to police reports, they found two people engaged in sexual contact in a parked vehicle. And police later confiscated a bag of heroin from the car, along with some marijuana and a crack pipe hidden on the female’s body.Police were called to a Barry Place address, one block east of Grant and south of Forest, at about 2:30 a.m.