Forty-five years after the lifeless body of 11-year-old Linda Ann O’Keefe was found among the cattails in Newport Beach’s Back Bay, police Saturday released a snapshot profile of a possible suspect in her killing generated by a medical laboratory using DNA evidence from the crime scene.

Police hope the profile will provide a break in finding Linda’s killer after an investigation spanning four decades has yielded few clues.

Virginia-based Parabon NanoLabs actually provided two profiles — one showing a man in his mid-20s and another detailing what he might look like today in his late 60s or early 70s.

The man has fair skin, blue or green eyes and dark blond or light brown hair, according to the profile.

The process uses DNA to calculate a possible suspect’s facial composite, gender, ancestry, freckles and skin, eye and hair color. The source of the DNA in this case isn’t clear.

Police agencies across the country have sought Parabon’s services to help crack cold cases using DNA evidence. Last year, the laboratory helped Costa Mesa detectives identify a suspect in the 1997 slaying of 26-year-old Adrienne “Sunny” Sudweeks.

Linda Ann O’Keefe, 11, of Corona del Mar disappeared July 6, 1973, while walking home from summer school. Her body was found a day later in Newport Beach’s Back Bay, police said. (Courtesy of Newport Beach Police Department )

Linda O’Keefe vanished July 6, 1973, as she walked home from summer school at what was then Lincoln Intermediate (now Lincoln Elementary) in Corona del Mar. Her body was found the next day. She had been strangled and discarded in the brush. She was still wearing the white dress adorned with blue flowers that her mother had sewn.

A girl and her mother who saw Linda walking the day she disappeared told detectives that she had stopped near the intersection of Marguerite Avenue and Inlet Drive, where a turquoise van was parked along the curb with its door ajar. The driver was described as a man in his mid-20s or early 30s with curly hair, police said.

It was the last time Linda was seen alive. A sketch of a “person of interest” was circulated but generated no leads.

On Friday, the Newport Beach Police Department began telling Linda’s story on Twitter in an effort to make progress in the case.

The series of tweets — written with Linda as the narrator — began with an introduction to the girl, her home on Orchid Avenue and her journey to summer school.

“We went with this Twitter platform speaking in Linda’s voice as a way to humanize this case again,” said police spokeswoman Jennifer Manzella. “It’s an old case from 45 years ago and it might be hard for people to form the emotional attachment to that, but we think Linda is due that.”

The tweets continued into Saturday morning, sharing details about Linda and chronicling the last hours of her life.

Linda, the middle of three daughters, loved crafts, playing piano and spending the day at the beach. She was a sensitive girl, according to her family, and took the loss of one of the family’s three cats a few months before her disappearance especially hard.

“Not all crying is the same, though. The last time I cried-REALLY cried-was a few months ago. We have three cats and one of them died. They told me she had cancer, but I don’t really know what that means. I missed her SO MUCH for weeks and weeks after she was gone.” #LindasStory pic.twitter.com/vBqplB1WWH — Newport Beach Police (@NewportBeachPD) July 6, 2018

During the search for Linda, her mother, Barbara O’Keefe, described her as “a sweet, shy girl who would never have voluntarily stayed away from home for anything like this length of time.”

Linda’s father, Richard O’Keefe, helped police and volunteers who scoured the community by helicopter, on foot and by car all night looking for his daughter.

Shortly before 10 a.m. July 7, a man who was surveying the Back Bay for a nature study discovered Linda’s remains. The red, white and blue bag she had been carrying was found nearby.

“The man is looking in the ditch on the east side of Back Bay Drive, searching for frogs in the cattails,” the Police Department wrote — in Linda’s voice — on Twitter. “Instead, he sees something small and pale. My hand. He sees my hand. He screams, trying to rouse me.”

A woman who lived on the bluff above where Linda’s body was found told detectives she heard a female scream “Stop, you’re hurting me” shortly after 11 p.m. July 6.

An autopsy determined Linda likely was killed shortly before or after midnight.

Police on Saturday urged anyone who recognizes the man in the Parabon snapshot to come forward with information.

“We hope this technology will lead us to Linda’s killer and give closure to Linda’s loved ones,” a detective said in a video posted on Twitter about the case.

Anyone with information about the case is asked to call the Police Department’s cold case tip line at (949) 644-3669.

“Here is a video about my case. About the evidence. About the clues and facts that will lead detectives to my killer. My name is Linda O’Keefe. What is his name?” #LindasStoryhttps://t.co/ccByaUlChw — Newport Beach Police (@NewportBeachPD) July 7, 2018

hannah.fry@latimes.com

Twitter: @HannahFryTCN