(CNN) -- Michael Skakel, the nephew of Robert and Ethel Kennedy, will be eligible for freedom Wednesday for the first time since his conviction for murdering his teenage neighbor Martha Moxley in 1975.

Skakel will go before a Connecticut parole board after serving 10 years of a 20-years-to-life sentence for bludgeoning Moxley to death with a golf club outside her home.

Her body was found after a night of partying with Skakel, his older brother Tommy, and other teenagers in an affluent gated community in Greenwich, Conn.

Both Skakel, now 52, and Moxley, were 15 at the time of the murder. Twenty-seven years later, Skakel was tried and convicted of the crime as an adult.

Martha Moxley's mother, Dorthy, told CNN she wanted Skakel to serve at least 20 years.

"I'd like him to stay in longer, if possible. Only 10 years of a 20-to-life sentence -- that doesn't seem right to me," she added.

Skakel has maintained his innocence. Yet, the girl's mother remains unmoved.

"People just don't want to be responsible for their actions," she said.

It is a view echoed by John Moxley, Martha's brother, who will speak on behalf of his family Wednesday morning before Connecticut's Board of Pardons and Paroles.

In a letter to the board, Moxley spoke of the toll his sister's murder had taken on his family and asked that Skakel's parole be denied.

"I believe that Michael Skakel is representative of the most dangerous aspect of our society in that he was raised in an environment in which he was exposed to and at some point embraced the mind-set that the rules of our general society did not then and do not now apply to him."

He added: "Michael has been incarcerated for 10 years, but Martha has been dead for almost 40 years and although the scales of justice will never be balanced, Michael Skakel should be incarcerated for the balance of his life."

Skakel's attorney, Hope Seeley, told CNN in a statement: "Michael's conviction was a miscarriage of justice, but that aside, his further incarceration would also be a miscarriage of justice since he should have been sentenced as a juvenile with a maximum sentence of four years. There has never been a person more deserving of parole than Michael Skakel. His track record during the past 10 years shows the person we all know him to be -- caring, generous, and committed to his faith, family and friends."

Seeley said the defense has submitted 65 letters to the board on Skakel's behalf. Several of the letters describe him as a model prisoner and deeply religious, and said he has taken an interest in mural painting while in prison.

A letter from Robert F. Kennedy, Jr. calls Skakel "kind, forgiving, and guided by God in all his actions and transactions. He is as incapable of violence or injuring another human being as any person I've ever met."

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