MADISON, Wis. -- The former University of Wisconsin student accused of killing Madison resident Joel Marino last winter entered a guilty plea on Monday.

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Adam Peterson, 20, was accused of fatally stabbing Marino in his home last January in what authorities believe was a robbery attempt.

Peterson entered the plea to one count of first-degree intentional homicide during a hearing in Dane County Circuit Court. Peterson is a Stillwater, Minn., native who dropped out of the University of Wisconsin-Madison last year.

Dane County Judge James Martin immediately sentenced Peterson to life in prison, but a separate trial within the next few months will decide Peterson's true fate. Prosecutors told the court that they will recommend no more than 40 years behind bars before Peterson could be eligible for release.

Lou and Debbie Marino, Joel Marino's father and stepmother, were both in the courtroom when the plea was entered. Marino's family said that they hope for a life sentence.

"If it was my choice, he’d spend the rest of his life in prison," said Lou Marino, after the plea hearing. "He took 53 years from my son's life. I would hope the judge would consider that."

Lou Marino said his son's death has dealt a blow to his family.

"Nothing will ever bring closure to the family in this situation. We're just going to have to learn how to live with it and deal with it day to day," said Lou Marino.

Joel Marino, 31, was a musician and technical representative for a medical device company.

During Monday's hearing, Peterson answered the judge's questions about his plea, but made no other statements. Peterson spoke firmly and confidently when responding to the judge and admitted in court that he meant to kill Marino.

Peterson's attorney, assistant public defender Dennis Burke, told the court his client had a rough go in jail -- including a suicide attempt -- and he was "anxious to move on to prison."

Burke said that his client is suffering from mental illness but was able to tell right from wrong when he stabbed Joel Marino to death in his home in January. He said that the plea comes against his legal advice.

Burke said last week that Peterson's defense was prepared to concede at trial that his client killed Marino, but that he should be found guilty of a lesser charge.

Prosecutors said they have tapes of Peterson speaking with his parents from jail in which he admits killing Marino during an attempted robbery.

Peterson left the Dane County Jail and was to then enter the state's prison system. He was moved to the Dodge County Correctional Institute on Monday night. He will return to court within the next 60 to 90 days for a final sentencing hearing.

Stay tuned to WISC-TV and Channel 3000 for continuing coverage.