Hoon "Scott" Kang, 20, was vacationing in Tokyo with friends when he was found lying in an emergency stairwell with blood trickling from his left ear early on Aug. 27. He died three days later in a hospital, never having regained consciousness.

Japanese authorities initially concluded that he fell down the stairs accidentally. Kang's family believes he was a victim of something much more sinister. They learned Monday that Japanese police had reopened the investigation, at the prodding of the U.S. Embassy in Japan.

"They tried to say it was an accident," said his father, Sung Kang, 48, reached by phone Tuesday in South Korea, where he is visiting relatives. "But when I visited the police office and I saw the pictures of the accident area, I knew this was not an accident."

Police showed the Kang family a surveillance video from an elevator in the building that housed the restaurant where Scott Kang had stopped. The video shows Kang in the elevator shortly after 11 p.m. with a man in a black hat. Kang gestures with both hands out, as if to say "I don't have anything," and the man appears to punch Kang in the stomach, his father said.

His body was found around 1:30 a.m. in the stairwell between the sixth and seventh floors. He remained in a coma due to severe head trauma until his death Aug. 30.

A representative of the U.S. Embassy in Japan declined to talk about the case except to say it is the subject of an ongoing investigation.

The Kangs believe the Japanese authorities discriminated against them by not taking the case seriously. An article about Kang's death recently appeared in the Chosun Daily News, a Korean newspaper in Duluth.

Pastor Hang Soon Park of the Salt and Light Presbyterian Church said the congregation has held prayer vigils for the family. Kang's parents plan to return home from South Korea next week. Meanwhile, their qualms about the Japanese investigation linger.