MADISON, Wis. -- A suspect in a high-profile stabbing death that frightened Madison residents was ordered jailed on a $1 million bail Tuesday.

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University of Wisconsin-Madison dropout Adam Peterson, 20, showed no emotion and said nothing during his initial appearance Tuesday in Dane County Circuit Court.

Instead of the traditional jumpsuit, he wore a sleeveless one-piece black garment given to Dane County inmates considered at risk of committing suicide.

Court Commissioner Todd Meurer accepted a prosecutor's recommendation to impose the $1 million cash bail on Peterson.

Peterson's Public Defender Dennis Burke did not challenge the motion.

Meurer scheduled a status hearing for the case on July 9.

Police said that Peterson fatally stabbed Joel Marino in his Madison home on Jan. 28. He was arrested at his mother's home in Grant, Minn., near Stillwater and charged last week. He was extradited to the Dane County Jail in Madison, where he was processed on Monday.

Peterson's father, Melvin, said that he believes his son is suffering from mental illness.

Peterson's father said that his son had a psychotic episode in March that prompted his twin brother to call Madison police.

Authorities said that they checked on Peterson's welfare but are offering no details about how they handled the incident. Afterwards, Adam Peterson checked into a hospital's psychiatric ward for a week before moving back to Minnesota.

The incident was serious enough to land Peterson's name on a bulletin that alerted officers that he could have mental health problems.

Police spokesman Joel DeSpain said that the 911 call alone wasn't enough to suspect Peterson killed Marino.

Marino's Parents React To Arrest

The parents of the 31-year-old Marino said the charging is bittersweet because there is still so much pain over their loss, WISC-TV reported.

"You're elated in one respect that they captured or arrested the person and at the same time you still have a hole in your heart for losing your son and never seeing him again," said Lou Marino, Joel's father.

Joel's stepmother, Debbie Marino, shared similar sentiments. "Just a hole in your hear that just doesn't mend and I don't think it will ever mend. it will always be there."

Lou and Deb Marino appeared on Fox News on Monday night from WISC-TV's studios and told Greta Van Susteren that there was no connection or relationship between Peterson and Joel Marino

The Marinos said their son an incredibly caring, loving man who went out of his way for others.

Authorities: DNA Played Role In Suspect's Arrest

Apparent DNA evidence played a critical role in identifying Peterson as a suspect in Marino's death.

Police officials said Peterson was arrested after he refused to provide a DNA sample to investigators.

Capt. Jim Wheeler, of Madison's South Side Police District, said that Peterson's refusal to voluntarily give authorities a DNA sample so that he could be excluded from a list of potential suspects was the red flag that accelerated their investigation into him, which led to his arrest.

Police got DNA samples from more than 50 people during their investigation, WISC-TV reported.

Wheeler said that a mental health-related police contact, along with a general suspect profile, got Peterson onto a list of people without alibis asked to provide DNA swabs.

Wheeler said that Peterson refused so detectives dug into him and reexamined some old information and it all started to click.

Police then got a search warrant for Peterson's DNA and arrested him the same day.

Peterson is expected to make his initial appearance this week.

A criminal complaint filed last Friday said that Peterson's DNA matches DNA evidence taken from the murder weapon -- a knife -- and a hat and a backpack found near the scene of Marino's slaying.

So far Peterson hasn't been linked to two other unsolved killings of young women in the Madison area, but police spokesman Joel DeSpain said that doesn't mean Madison has killers on the loose. DeSpain points to Peterson's arrest.

"The (alleged) murderer was not wandering the streets ... walking the streets of Madison. He was in Minnesota. So, I think for people to say there's a killer or killers on the loose in the streets of Madison. Nobody knows. Is the person who killed Brittany Zimmermann ... are they still here? We don't know. Is the person who killed Kelly Nolan still here? We don't know."

Brittany Zimmermann was killed at her home on April 2. Kelly Nolan disappeared from downtown and was found in the Town of Dunn on July 9, 2007.

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