SANTA ANA (AP) — As a county gravedigger, Andrew Trejo has helped numerous families bury their loved ones. Neary 28 years after his mother disappeared, he will finally get to do the same.

Last year, he and four other relatives gave DNA samples to be checked against unidentified human remains recovered by law enforcement agencies in Orange County, California, and elsewhere in the hopes of finding Kristyne Olivia Trejo, who left her family home in Santa Ana in 1988 and never returned.

Their DNA turned out to be a match with a skull and arm bone found in 1989 in the desert of nearby San Bernardino County.

“I’m sad that we’re not bringing her home alive, but at least we have her, and can properly lay her to rest and we can start the process of healing,” Trejo told reporters.

It’s the first success for Orange County’s “Identify the Missing” Day held last October by the coroner’s division of the Orange County Sheriff’ Department. Cheek swabs were collected from relatives of some 34 missing people to be compared with the DNA of unidentified human remains.

Such events have also been held in Michigan, New York and elsewhere as investigators turn to ever-improving DNA technology to forge connections between people reported missing and unidentified remains.

One of the challenges is geography. Relatives might report a family member missing in one jurisdiction, with a match later found in another state or county.

Bob Hunter, deputy coroner investigator for San Bernardino County, said a similar DNA gathering event held last year in his county might soon yield a similar match to remains found in another California county.

“There are so many unidentified people who need to be identified,” Hunter said, adding that his county has remains of about 600 unidentified people. “This needs to be a national event annually for every county in the United States.”

There is an open homicide investigation in the death of Trejo, he said.

Trejo, who worked as a waitress, was living with her parents and two children in Santa Ana when she disappeared after leaving for a group meeting for recovering addicts, Andrew Trejo said.

He expected her back later in the day to attend a ceremony marking his completion of the fifth grade, but she never made it.

For years, he would wait for her after returning home from school. He remembered how she loved oldies music and how pretty she was.

Trejo said he knew how much she loved him and his younger sister. She would never have simply walked out, he said.

After a while, he said he stopped believing she would return.

“I always wondered what happened, how and who could have done this to her,” he said. “If justice isn’t served here, I know that the Lord will take care of it.”