One prosecutor put it bluntly: Robert Landis is the worst drunk driver in Chester County.

He's been arrested eight times since 1981, half with his blood-alcohol triple the legal limit. In 2010, Landis promised a judge he had found sobriety through prayer. "This disease," he said, "is out to kill me."

But first, it led him to kill someone else.

On Monday, Landis admitted causing the death of a motorcyclist last year in Westtown Township. Prosecutors are seeking up to 17 years in prison.

After declining for years, drunken-driving deaths have hit a plateau or crept up. Pennsylvania averages more than one a day.

Landis stood apart. The county's top prosecutor used his case to call for longer prison terms. His eight offenses stunned even the judge who took his plea.

"Mr. Landis, that's almost to the absurdity level, isn't it?" County Court Judge Anthony Sarcione asked.

"Yes, your honor," replied the 50-year-old Landis, dressed in light jeans, white Velcro sneakers, and a wrinkled white T-shirt.

"And now it takes a life," the judge said.

Landis, a West Chester resident, pleaded guilty to homicide by vehicle while driving under the influence and driving without a license.

During a news conference after the hearing, District Attorney Thomas Hogan pressed state lawmakers to impose higher mandatory minimum sentences for repeat drunken drivers like Landis who cause a crash that kills.

He said the message to chronic offenders needs to be simple: "We will warehouse you."

As he spoke, Diane Crowley, stood beside the lectern, her head quivering until she calmed herself with a deep breath.

Her son Liam, 24, was killed in April 2013 when his motorcycle slammed into Landis' truck along Wilmington Pike as Landis pulled into oncoming traffic after leaving a local bar.

"Unless we all begin right now to make changes . . . there is a ridiculously strong chance that someone that you love will be hurt or killed by a drunk driver," Crowley told reporters. "Or maybe you yourself will be the offender. And that would certainly be a different kind of hell."

Landis logged his first DUI in 1981. With each that followed - in 1990, twice in 1997, once in 2002, 2005 and 2009 - he was given harsher penalties, court documents show.

Early jail sentences ranged from two to 90 days. But he never served more than eight months in prison until he was sentenced for the 2009 offense, according to court records.

Over the years, the records show, judges used nearly every measure at their disposal - from electronic home monitoring devices to community service and jail time. With each sentence, Landis' license was suspended.

That didn't keep him from driving.

When he was pulled over in 2009 after swerving back and forth on Route 30 in West Whiteland Township and taking a turn so wide that his vehicle nearly struck a median, Landis told the officer that he didn't have a license. The officer asked why.

"For this," he said, according to the affidavit. "For DUI."

At the time of the crash that killed Crowley, it had been about two years since Landis finished serving his sentence for the 2009 arrest.

Officials said he was eligible to have his license returned, but had not filed an application for an ignition interlock system to be installed in his truck. Letters from the state Department of Transportation explaining how he could do so were found in his Dodge Ram the night of the 2013 crash along with several beer cans, empty and unopened.

His blood-alcohol level that night was 0.283 percent, more than three times the legal definition of drunken driving.

Assistant District Attorney Charles Gaza said that he had seen one other offender with more DUIs, Landis struck him as the county's worst drunken driver because of how "overwhelmingly" intoxicated he has been behind the wheel and the frequency with which he causes crashes or near-crashes.

Landis is scheduled to be sentenced in May.

Drunken-driving deaths dropped nationally and on the state level during the last decade, according to the National Highway Traffic Safety Administration. Those statistics also show the number of deaths remaining static in Pennsylvania, at about 400 per year, from 2009 to 2012.

Hogan said Monday that the legislation he has drafted could help save lives by deterring drunken driving, but more likely by keeping the most dangerous offenders off the road longer.

The state's mandatory minimum sentence for homicide by vehicle while driving under the influence is three to six years.

Under the legislation proposed by Hogan, those who have received three DUIs and cause a fatal crash on their fourth would be subject to a mandatory seven-year minimum and a 10- to 20-year maximum. The terms would apply for each fatality, making the mandatory minimum for a crash that killed four people 28 years.

Sen. John Rafferty (R., Montgomery) has reviewed the legislation and plans to draft a bill soon that will likely combine Hogan's wording with similar measures drafted by others, according to his chief of staff.

Barron Lerner, a faculty member at New York University's Langone Medical Center who has authored a book on the history of drunken driving, said mandatory minimum laws were useful for keeping bad drivers off the street but typically do little to deter crime.

"There's not a lot to say that if you put someone away for five to 15 years, that they are less likely to get drunk and drive when they get out," Lerner said.

That hasn't stopped Liam Crowley's parents from backing stricter legislation.

Patrick Crowley said he has spent the last year grappling with the idea of justice for his son, wanting the worst for Landis but knowing that would not be enough.

What would be, he said, is prevention.

Patrick Crowley said he was hopeful that legislation could be named after his son, who he said at 6-foot-4 commanded a large presence without dominating a room.

Before his death, the Chesterbrook man had worked in information technology and had just moved in with his girlfriend.

Like his father, he loved music, and took to jazz guitar, often playing in a band with his older sister. He had an inquisitive and creative mind, and wrote his own music, the father said.

A year after their son's death, Diane Crowley can now wake up in the morning without the sharp pang of loss, she said. It washes over her slowly.

"It's like, yeah, Liam's dead," she said. "And sometimes I even think Liam's still dead."

She said she senses that he is with her but is still measuring the void. She said forgiveness for the man who killed him, and whom she watched plead guilty while she wiped away tears, is not something she needs.

"We don't even know what we lost," the mother said. "Because we don't know what would have been."