Liz Dunning reaches for the hand of her husband, Paul, just yards from the finish line of the Rock 'n' Roll Marathon. The race fell on what would have been her mother’s 70th birthday. (Michael S. Williamson/The Washington Post)

Liz Dunning awoke before her alarm sounded. She knew she would.

She got out of bed at 4:30 Saturday morning and dressed for what was to come, pulling an orange T-shirt over her layers. “RUN LIZZIE RUN,” it said, on front and back. She brewed a pot of coffee, then sat on the kitchen floor to lace up her purple sneakers. Her husband, Paul, leaned down to kiss the top of her head.

“I’m very proud of you,” he whispered.

“Good luck with the guys today,” she said, referring to their sons, ages 3 and 7.

Liz Dunning holds vintage family photos of herself and her mother, Nancy Dunning, who was slain by a serial killer in 2003 in Alexandria. (Michael S. Williamson/The Washington Post)

“Good luck,” he smiled, “with running a marathon today.”

If life had gone as it was supposed to, she wouldn’t have run a marathon on this day. She would have woken up and called her mother, Nancy, to wish her a glorious 70th birthday. They would have seen each other for lunch or dinner or a party. They would have shared margaritas and talked about the kids. They would have discussed their next big trip together. They would have laughed.

But none of that happened because, on the morning of Dec. 5, 2003, Nancy opened the front door of her Alexandria home and was shot to death by a stranger.

Not until 2014 did investigators arrest Charles Severance, an eccentric and bitter man who prosecutors said chose his victims for their social status. In a case that drew national attention, he was convicted of Nancy’s killing and two other murders, and sentenced to life in prison.

For years, Liz had never publicly told the story of her bond with Nancy or the depths of her anguish when it was fractured. But after the trial, she said, she felt free to honor her mom in a new way.

She decided that 2017, when she would turn 40 and her mother would have turned 70, had to be the right time. She wanted to do something hard — something that demanded sacrifice. She had always liked to run, so maybe a marathon. She’d completed one before, at 23. Nancy had come to support her then, finding five spots along the route to give her daughter orange slices and shout the same words of encouragement: “Run, Lizzie. Run.”

After Christmas, Liz searched for upcoming races. And there it was: On March 11, her mother’s birthday, the Rock ‘n’ Roll Marathon in Washington. She soon connected another two dots. A marathon covers 26 miles; she and her mother had together shared 26 years.

Liz Dunning, center, is embraced outside an Alexandria courthouse in 2015 after reading her statement in the trial of Charles Severance, who was charged with her mother’s murder. Severance was found guilty and sentenced to life in prison. (Matt McClain/The Washington Post)

“Oh,” she thought, “I have to do this.”

She launched a blog to share memories of her mother and raise money — more than $28,000 — for the Brady Campaign to Prevent Gun Violence.

Now, before dawn Saturday, Liz was riding in a Lyft car from her home in upper Northwest Washington to the starting line on Constitution Avenue. She stepped out into a wind chill of 17 degrees.

She slipped on a snowcap and found a spot in front of the National Museum of American History as Eminem boomed from nearby speakers. She bounced and stretched. She grew quiet.

It was time.

Liz found her place amid hundreds of runners who didn’t know who she was or why she’d come. As the 10-second countdown for her group began, she glanced up at the clear, blue sky.

***

Each morning, Nancy’s voice rose from the kitchen.

In a silly, operatic tone, she would sing to her sleepy-eyed son and daughter — about the raisins in their oatmeal, the spelling test at school, anything at all. They’d roll their eyes. They’d giggle.

To the public, so much of Nancy’s legacy was defined by details about her death and the years of uncertainty that followed before the serial killer who took her life was caught.

To Liz, she has never been defined by any of that. Nancy, at just over 5 feet tall, was the striking, compassionate, fiercely optimistic woman with light blue eyes and blond hair who sang to her kids about oatmeal. She was, to Liz, her dearest friend.

Mother and daughter seldom argued, but not because they didn’t disagree, especially in Liz’s teenage years. Nancy just had a way of sensing her daughter’s moods — of saying just the right thing.

Nancy was so sad in the months before her daughter left for college in Ohio that Liz made her a collection of mix tapes, mostly filled with R.E.M. Nancy would listen to “Everybody Hurts” when she desperately missed Liz, then call just to say she had listened to it.

Even as her social demands grew — selling real estate, organizing charity drives, attending events with her husband, Alexandria’s then-Sheriff James Dunning — Nancy remained acutely focused on her kids.

She began to prop open a cardboard box on her dining room table and, day after day, fill it with items she would send her daughter at the end of each month: olive bread, a new brand of dark coffee, an article about a band they should see together during summer break, a soft pair of socks that might comfort her before exams.

To celebrate Liz’s 20th birthday and Nancy’s 50th, they flew to Miami and drove in a white convertible to Key West. They ate Key lime pie with every meal and went on a snorkeling excursion that Nancy immediately aborted. “I’m 50,” she said. “I don’t need this.”

Nancy picked up a six-pack of Pete’s Wicked Ale, which Liz insisted was the most fashionable choice.

The pair sat on the second-floor balcony of the bed-and-breakfast and rested their feet on the rail. Her mother’s toenails, she has never forgotten, were painted blue, like the ocean. They watched people pass and told jokes. They considered all the happy times ahead and imagined the birthday trips to come.

When Liz reached 40 and Nancy 70, mother and daughter wondered, what might they do together then?

***

The call came just after noon on that winter day 14 years ago.

“Liz, mom’s dead,” said her brother, Chris. “She’s been killed.”

Soon, she was in a co-worker’s car, being driven to her parents’ home.

Liz had last seen her mom just days earlier at the National Theater for a performance of “Mamma Mia!” They had danced together in the aisle.

“This must be a mistake,” she said.

Liz never made it inside. Chris stopped her in the road.

He convinced her it was true. “She’s dead,” he said.

Chris and James were supposed to have met Nancy for lunch, but when she didn’t show up, they drove to the house. Near shopping bags filled with items she had just bought for needy children, they found her body.

Liz spent that night on her knees in a hotel bathroom, forehead pressed against a cold, tear-slicked ceramic tile floor.

Liz searched for ways to cope. She went to therapy alone and with her father and brother. She placed a bird feeder in her back yard so she could stare at cardinals just like the ones that had lived behind her parents’ home. She fell in love with her eventual husband, Paul, who treated her like Liz instead of the girl whose mom was murdered.

She wrote letters to Nancy, too.

“I needed her to know what was happening,” said Liz, who now works at a nonprofit organization in Washington, where she gives grants to teachers in public schools.

Liz’s father often felt lost, she said. People stared. They spread rumors. Once, a stranger approached Liz in the grocery store: “Your dad was responsible.”

He retired before moving to South Carolina in 2007. Five years later, at 62 — with the case still unsolved — he died of heart failure. Liz blames that on the murder and its aftermath.

Two years later, well after Liz had given up hope that the killer would be found, she got a call about a suspect. She compared images of Severance with footage taken of a man who might have followed Nancy out of a Target shortly before the shooting.

Their hairlines, she thought, looked identical.

She sat through nearly every minute of the trial, convinced that investigators had found the right man. Before sentencing, she mentioned her own sons to the jury.

“They’ll never know her,” Liz said.

Liz once feared that she couldn’t become the mother to her children that Nancy was to her. Instinctively, it seemed, Nancy always thought of her children first. Could she do that, too?

She and Paul refused to let her mother’s memory fade. For an annual luminaria lighting last year, the kids drew pictures of her and Liz on the paper bags that held the candles. The couple took their older son to ride his bike in the Outer Banks near where Liz’s parents had also taught her how to ride. Their younger son calls Nancy “Grandma Happy Face” because, in so many photos, she’s smiling.

The kids didn’t know it, but they had helped push her to run the marathon, too. They would never meet Nancy, and someday, they would learn the terrible reason why. But the marathon might offer the kids — who wore bright orange shirts just like their mom’s — a lasting memory linked to their grandmother.

And so, they cheered their mother on at miles 15 and 21, and when she pushed through the finish line at 4 hours 29 minutes.

Exhausted, Liz didn’t say much.

She picked up a bottle of water and a granola bar, then retrieved her backpack. She pulled on her sweatshirt and limped through the crowd of runners basking in their finishes.

She had just run 26.2 miles in freezing, windy weather on the day of her slain mother’s birthday, but all of that could wait. Her thoughts, the first ones, were with her boys, who had endured the cold all morning.

“I know they’ve been through a lot,” Liz said, and as they came into view, she waved and limped faster.