A La Plata man charged in a hit-and-run accident that killed a Burtonsville woman and critically injured her husband could be the first person tried under a Maryland law that imposes tougher penalties for leaving the scene of a fatal accident, authorities said yesterday.

Keith L. Lee, 35, could be sentenced to 10 years in prison and fined $10,000 if convicted under a new law that makes hit-and-run with a fatality or serious injury a felony instead of a misdemeanor. Changing the offense to a felony doubled the maximum penalty.

"Every person has a moral and ethical obligation to render aid at the scene of a collision that they caused," Montgomery County State's Attorney Douglas F. Gansler said yesterday. "Now they have a meaningful legal obligation as well."

Lee, who has an extensive record of traffic violations that includes two convictions for driving under the influence of alcohol, was ordered held in lieu of a $150,000 bond yesterday in Montgomery County District Court, Gansler said.

Neris Roldan, 49, and her husband, George Roldan Sr., 55, were on their way to their family's annual Christmas Eve party in Rockville when the accident happened shortly after 7 p.m. They had got to Norbeck Road near Drury Road in Silver Spring.

Neris Roldan, who had studied to be a nurse and took care of elderly people, died of her injuries at Prince George's Hospital Center soon after the accident. Her husband, a chef, remained in critical condition last night at Suburban Hospital, unaware that his wife had died, his two children said.

Yesterday, relatives gathered in Rockville and reminisced about the couple. George Roldan had survived a bout with lung cancer four years ago, and the couple had been preparing to visit their native Puerto Rico next month for the first time in more than a decade.

As children, both Neris and George Roldan moved from Puerto Rico to the Bronx. They met in New York. Twelve years ago, they settled in Montgomery County. "They just wanted to get out and give us a new life, a better life," said their daughter Jessica Tolson, 23.

In the past year, the couple celebrated Jessica's wedding in May. This month the Roldans, along with 28-year-old son, George, had moved from Silver Spring to Burtonsville.

Next year, they would have celebrated their 30th wedding anniversary. They had a close marriage, their children said. Neris Roldan nursed her husband through two operations for lung cancer.

"She was a sweetheart," Tolson said. "Whenever someone needed a hand, she would reach five miles and give them a hand."

The couple spent much of their spare time with their grandchildren. There were three -- a 2-year-old and two 4-year-olds. Neris Roldan would take care of them on weekends.

The Roldans had their Christmas traditions, and this year they expected it to be no different. Christmas Eve would be spent at their niece's house. At midnight, they would open gifts. That is, everyone but Neris, who insisted on waiting until the next morning to open and hand out presents.

On Tuesday, Neris asked her son not to drive because it had started to snow. But he insisted on picking up a friend and meeting his parents at the party. His mother set off with her husband for the party.

Police are trying to piece together what happened next.

Police said a GMC pickup truck, headed east on a curved section of Norbeck Road, crossed the center line and struck the Roldans' westbound Saturn head-on. Police believe Lee was driving. The pickup was found at the scene.

Prosecutors said Lee, with a broken ankle, fled to his girlfriend's home in nearby Wheaton. He took her car to get away and police arrived minutes later, they said. Prosecutors said Lee was arrested after receiving medical treatment for his ankle. By then -- more than 24 hours after the accident -- it was too late for a breath test for alcohol.

Lee was charged with failure to remain at the scene of a fatal collision, speeding and failure to remain right of center on the road. Prosecutors expect to present the case to a grand jury within 30 days.

Prosecutors said Lee has an extensive traffic record -- 32 pages long -- including two convictions for driving under the influence of alcohol and three for driving with a revoked or suspended license.

Lee, who has 10 convictions in Montgomery County, is on parole until November 2005 on convictions for second-degree assault and burglary, prosecutors said.

The Maryland General Assembly enacted the hit-and-run law this year after a series of accidents.

"It's due, in part, to the lobbying of survivors who went to Annapolis and told their story of losing their loved one and then seeing the person responsible face little or no penalty," Montgomery County police spokesman Derek Baliles said.

Staff writer Matthew Mosk contributed to this report.

Neris and George Roldan Sr. were going to a family party when Neris Roldan was killed in an accident.