Yonegoro Nusumi

Yonegoro Nusumi is a victim Light kills in front of Raye Penber to prove to that he is really Kira. His death was not mentioned by L or any of the cops.

Cause of Death
At 3:00 PM on December 27, 2003, while wearing a hood to obscure his identity, Light holds Penber hostage in an underground section of the Shinjuku Station by killing Yonegoro Nusumi, an employee at a shop labeled "Cafeel" with a heart attack.

Nusumi had raped women but escaped a court conviction due to a lack of evidence, therefore Light feels justified in killing him. He is never seen or mentioned again.

Trivia
It is unknown whether or not Nusumi was actually a criminal due to light's hasty over reaction to some cases. He could have been working undercover so the police would'nt track him down. He also may have been wrongly framed for the crime. Or Light may have killed him and guessed he was a criminal. Though none of these have been confirmed.