Yoko Ono will again oppose the release of the man who nearly 30 years ago killed her husband, former Beatle John Lennon, and who comes up for parole next month, her lawyer said. Ono has consistently opposed parole for Mark David Chapman and has again sent a letter to the parole board, her lawyer, Peter Shukat, told the Daily News. Lennon was shot to death on Dec. 8, 1980, outside the famed Dakota apartment building just west of Central Park as he and Ono returned home from a recording session. Chapman - now 55 and serving a 20-years-to-life sentence for the slaying - is scheduled to be interviewed by a three-member parole board panel during the week of Aug. 9. It will be his sixth bid for parole. Due to his notoriety, Chapman is kept in a special unit apart from the upstate Attica prison's general population. He works as a porter, cleaning up offices, and assists inmates in one of the prison's law libraries.