In the little more than a year since his son died on a vacation in Tokyo, Sung Kang has returned to Japan four times to plead with local police to conduct a thorough investigation.

He has gathered some 6,000 signatures in support of his cause from other Korean-Americans at his Buford church and in his community. And he has hired a prominent Japanese attorney to help plead his case. In short, Kang is not giving up.

“I am going to try my best to get justice for my son,” Kang said. “My son’s death is not an accident. He was killed by somebody.”

Kang believes that his son, Scott Kang, was robbed and then fatally injured Aug. 24, 2010, after separating from friends in a high-rise building in the kabuki theater district of Tokyo. He was found unconscious lying at the bottom of a stairwell with a deep gash in his head and blood trickling from his left ear.

Tokyo police have labeled the death an accident from falling down the stairs.

The family said a surveillance video from the building, which appears to show a man punching Scott Kang in the elevator just a few hours before he was found, casts doubt upon that conclusion. The family believes he was attacked by the man in the video and then shoved down the stairs.

Tokyo police let Sung Kang review the surveillance tape at the station, but they have since refused to hand over a copy.

Kang thinks Japanese authorities want to sweep the case under the rug because they don’t want to frighten other tourists.

Kang and family friend Ray Wozniak plan to return for the fifth time to Japan some time next year and hold a news conference in Japanese to help sway public opinion there in their favor.

The attorney they have hired, Maiko Tagusari, is Secretary General of the Federated Bar Associations of Japan. They hope she also might be able to exert some influence on the local government officials and the police. Tagusari had not responded to emails seeking comment by press time.

“We are forging ahead,” Wozniak said. “Neither Mr. Kang nor I are flagging in our efforts to get to the truth of this tragedy.”