(Update: Police arrest suspect in fatal stabbing of Logan Circle jogger)

A woman jogging in the Logan Circle neighborhood in Northwest Washington was fatally stabbed Tuesday evening in what police said was probably a random attack.

Wendy Martinez, 35, was attacked just before 8 p.m. in the 1400 block of 11th Street NW, near O Street NW, police said. She staggered into a nearby takeout restaurant, where patrons tried in vain to save her life.

D.C. Police Chief Peter Newsham said that, at this point in the investigation, police think the assailant was a stranger to Martinez. He said it did not appear that the attack was part of a robbery attempt. Police launched a search for the killer, but no arrest had been made as of Wednesday evening.

Martinez’s mother, Cora Martinez, said her daughter was an ambitious and vibrant young woman. She was working her dream job with a fast-growing start-up and got engaged last Wednesday.

“She was living the most beautiful moment in her life; it was the happiest last seven days,” Cora Martinez said.

Wendy Martinez was born in Nicaragua and raised in West Palm Beach, Fla. She loved to travel and was extremely proud of her Hispanic heritage, her mother said.

At a Wednesday news conference, Newsham said Martinez, who lived in the area of the attack, was an avid runner known to run for miles in the city. He said the area where the incident took place is a “very safe neighborhood.”

The chief called the attack “one of those unsettling incidents that sometimes happens in large cities.”

Cora Martinez said her daughter ran every day and had participated in six marathons. She said her family is trying to find beauty in the fact she died while running.

“It doesn’t make sense — she was a pure, innocent victim,” Cora Martinez said. “She didn’t have any issues with anyone.”

After she was stabbed, Wendy Martinez made her way into a Chinese American restaurant. The owner described a frantic scene, saying Martinez approached the counter but could not speak. He said some customers began CPR and other first-aid methods. Newsham said that a nurse was among them.

“They did the best they could, but she passed,” he said.

Newsham said that there are many video surveillance feeds from businesses and homes in the area, and detectives were checking them.

The chief said there were reports Tuesday night that there was more than one assailant involved, but police eventually determined that there was a single attacker. He said the confusion may have been the result of people running in fear from the scene.

Newsham said the killer is described as a black man wearing a mustard-colored shirt that went to his thigh area, along with dark-colored sweatpants that were slightly rolled up. The man wore white socks and light-colored sandals, according to Newsham. He fled south on 11th Street NW.

Police said that a knife was recovered at the scene.

Martinez graduated from Georgetown University with a master of arts in Latin American studies in 2012, according to a university spokesman.

Her mother described Martinez as a go-getter. She earned an internship on Capitol Hill with Rep. Mario Diaz-Balart (R-Fla.) after graduating from Florida Atlantic University in 2006, her mother said. From there, Martinez worked at the Nicaraguan Embassy, the Organization of American States and the Inter-American Development Bank before joining FiscalNote — a District-based management and technology company — two years ago.

She was promoted at FiscalNote last year and most recently held a position as its chief of staff.

On its Twitter account, FiscalNote wrote that staffers were “shocked and deeply saddened to learn that [Martinez] was killed last night.”

“Wendy was an invaluable member of our team and a vibrant member of the community,” the company tweeted.

Martinez’s 29-year-old brother, Juan Carlos Martinez, said Wendy loved living in the District and always found ways to help the people around her.

“She was a great role model, a perfect daughter, a great sister,” he said. “A wonderful member to society and the community in Washington D.C.”

Her death comes as the Washington region has experienced more than 190 homicides this year, according to tracking done by The Washington Post. Of those, more than 100 have been in the District, mainly in Southeast and Northeast Washington.

The area around Logan Circle has a relatively low crime rate, with few violent crimes. Most of the incidents in the area involve vehicle break-ins.

On Wednesday morning, Jessica Dillman, 34, placed flowers outside the restaurant where Martinez went for help.

Dillman — who lives less than a block away — said she also is an avid runner. The block where the woman was stabbed is part of the “safe route” she takes when she doesn’t want to run too far at night, Dillman said. She said she also carries a knife for her protection when she runs.

“I’m trying to be safe, and it’s just scary because women aren’t safe,” she said. “It’s scary, it’s scary for all of us.”

When asked whether she would change her safe route, Dillman offered a sobering response: “I don’t think there is a safe route for women.”

Peter Hermann, Marissa J. Lang and Jennifer Jenkins contributed to this report.