Interviews with more than a dozen witnesses in the shooting death of a 31-year-old Punahou man killed while cleaning his car Friday have yielded no clues about a possible motive, police said yesterday.

Twelve hours of interviews with friends and relatives also have not helped police find a motive, or the identities of three men who allegedly beat and shot Jason Nam to death, police said.

Nam, a delivery truck driver for the Govinda's Fresh Juices company and a bodybuilder, was described by co-workers as very reliable and someone who always showed up to work, police said yesterday.

Searches of Nam's apartment and car did not turn up anything that might suggest why anyone would want him dead, police said.

At 4 p.m. Friday, three men pulled up in a black Nissan Maxima at the apartment building at 1709 Beretania St., where Nam was cleaning his car in the building's parking lot.

After a brief argument and a struggle, one of the assailants hit Nam with a bat, and the others dragged him behind his car, where he was shot in the neck.

Nam, who had won a bodybuilding competition in recent years, is the older brother of mixed martial artist Tyson Nam, police said yesterday.

Anyone with information about the case is asked to call the department, police said.

Reach Peter Boylan at pboylan@honoluluadvertiser.com.