New York (CNN) -- Mark David Chapman, John Lennon's killer, was denied parole for the sixth time Tuesday, according to the New York State Division of Parole.

A three-member panel of parole board commissioners conducted a video conference interview with Chapman from their offices in Rochester.

In their written comments, the commissioners told Chapman they had concerns "about the disregard you displayed for the norms of our society and the sanctity of human life." After considering the action he took in 1980, they concluded Chapman's "discretionary release remains inappropriate at this time and incompatible with the welfare of the community."

Chapman's latest request for freedom comes just months short of the 30th anniversary of the death of the former member of the Beatles.

The last time Chapman was up for parole, in 2008, the New York State Division of Parole issued a release saying his request was denied "due to concern for the public safety and welfare."

He also was denied parole in 2000, 2002, 2004 and 2006.

Chapman, 55, is serving a sentence of 20 years to life in prison for the shooting death of Lennon outside Lennon's New York City apartment on December 8, 1980.

He has served 29 years of his sentence at the maximum-security Attica Correctional Facility, where he is held in a building with other prisoners who are not considered to pose a threat to him, according to officials with the state Department of Correctional Services.

He has his own prison cell but spends most of his day outside the cell working on housekeeping and in the library, the officials said.

For the past 20 years he has been allowed conjugal visits with his wife, Gloria.

The visits are part of a state program called "family reunion" that allows inmates to spend up to 44 hours at a time with family members in a special setting. Inmates must meet certain criteria to receive the privilege.

Chapman has not had an infraction since 1994, said Erik Kriss, spokesman for the Department of Corrections said last month.

"He goes about his business, doing his prison job and without any fanfare," Kriss said.

Yoko Ono, Lennon's widow, in previous years has submitted a letter requesting that parole be denied.

Chapman is next eligible for a parole interview in August 2012.