For more than 24 years, Dee Ziegert has wondered about the man who killed her daughter, Lisa, who vanished in April 1992 from the Agawam card shop where she worked and then turned up murdered four days later in a wooded area nearby.

Was her killer a big guy? Did he overpower her? One thing she never considered, Ziegert said, was the suspect’s face.

Now, Ziegert, investigators, and the public have a potential picture of the woman’s murderer because of technology that examined DNA evidence taken from the crime scene and transformed it into a composite sketch.

“It’s overwhelming,’’ Ziegert, 72, said Wednesday in a phone interview. “I said to someone, ‘It takes your breath away in a bad way.’ ’’

Hampden District Attorney Anthony D. Gulluni revealed the sketch Wednesday during a news conference in which he also announced a tip line dedicated to solving the murder. He said this is the first time the technology has been used in Massachusetts.

“That’s the likeness of the person we want to find,’’ Gulluni said in a phone interview. “We’re just now able, through the brilliance of this technology, to introduce what we think is a significant development in this case to the public.’’

Authorities have been searching for Lisa Ziegert’s attacker since April 15, 1992, when she disappeared from her part-time job at Brittany’s Card and Gift Shoppe in Agawam. Ziegert, 24, was a teacher’s aide at Agawam Middle School who wanted a career in special education.

Her disappearance was discovered the next day when a store clerk found the business unlocked, the lights on, and money still in the cash register, the district attorney’s office said.

Ziegert’s purse and school work were found inside the store, and her car was parked where she had left it, authorities said.

On April 19, 1992, Ziegert’s body was found about four miles away in a wooded area off Route 75. She had been raped and had suffered stab wound to her throat, according to authorities.

The sketch was created by Parabon NanoLabs Inc., in Reston, Va., which mines the information contained in DNA to predict traits like eye, hair, and skin color, face shape, and ancestry.

The technology, known as the Snapshot Forensic DNA Phenotyping Service, found Ziegert’s assailant likely descends from ancestors who lived in Northern and Southern Europe, has fair or very fair skin, brown or hazel eyes, brown or black hair, and freckles.

By pinpointing these details, Gulluni said, investigators can also exclude people who don’t have those characteristics.

Ellen Greytak, the laboratory’s director of bioinformatics, said the system cannot account for certain features such as weight and, by default, generates sketches showing a person at age 25. In Ziegert’s case, the firm also created a sketch depicting the suspect at age 50.

Greytak said the images are scientific approximations of a person’s appearance based on DNA, and not an exact depiction.

“It’s not intended to be the driver’s license photograph of that person,’’ Greytak said.

The technology has been available to law enforcement officials for a little more than a year-and-a-half and has been used in more than 60 cases worldwide, Greytak said. It is used to create sketches of suspects whose DNA doesn’t match samples in law enforcement databases and to generate images from unidentified remains, she said.

The DNA evidence submitted to create the sketch of Ziegert’s killer was collected from her body and the woods where she was found, Gulluni said. Over the years, the DNA profile has been compared to databases maintained locally and abroad without generating matches, he said.

Investigators have been working with Parabon NanoLabs for several months, and Gulluni said he saw the sketch for the first time last week.

“We’ve never forgotten Lisa,’’ he said. “It’s such a tragic case.’’

Gulluni urged anyone with information to call the tip line at 413-333-9148, contact Agawam police, or send an anonymous message by texting the word, “crimes’’ (274637) and beginning the note with the word, solve.

Dee Ziegert said she and her husband, George, saw the image for the first time Tuesday at the Agawam Police Department. She said she carries her daughter’s death with her every day.

“It never heals,’’ Ziegert said. “It’s always there.’’

Laura Crimaldi can be reached at laura.crimaldi@globe.com. Follow her on Twitter @lauracrimaldi.