More than 30 years. That’s how long John Nellans spent agonizing over what had happened to his 19-year-old son, who went missing in 1985.

Then, about a month ago, he was visited by officials from the San Diego County Medical Examiner’s Office. He was told that DNA samples his son’s sister had submitted more than a decade ago had helped investigators identify a body that was found in a wooded area of Clairemont in 2000. It was Nellans’ son, who was also named John but went by JP.

It wasn’t the ending the father had hoped for, but, he said Monday, “It is some closure for our family, and we’ve been waiting a long time for this.

“I hope other people don’t have to wait 30 years like I’ve been for this closure.”

The El Cajon resident shared his story in the hopes of motivating families with missing loved ones to attend the county’s first Identify the Missing Day, which is to be held at the Medical Examiner’s Office on Saturday.

Investigators are asking friends and relatives to visit the Overland Avenue facility, where they can file a missing persons report, update old reports with more information and submit DNA samples that will be run through a database of John and Jane Does that have been found across the United States. The event is free.

“Every case is a jigsaw puzzle,” said Chief Medical Examiner Glenn Wagner. “There are parts missing, and it’s our job, working with many, many disciplines, to put as much of that together.”

Chief Medical Examiner Dr. Glenn Wagner encourages families with missing loved ones to contact the Medical Examiner’s Office. lyndsay winkley u-t

Julio Estrada, supervising medical examiner investigator, said family members who have attended similar events in other counties have brought forth information that helped investigators crack cold cases.

“We’re hoping that we can do at least the same thing,” he said. “Even one (solved) case will be a story of success for us.”

Identify the Missing Day Where: San Diego County Medical Examiner’s Office at 5570 Overland Ave. in Kearny Mesa When: Saturday from 9 a.m. to 3 p.m. What to bring: Information that might help identify the missing, including photographs, medical records and dental records Two blood relatives willing to provide a DNA sample

There are 3,175 active missing persons reports dating to the 1950s in San Diego County, but experts believe there are many more who were never reported missing. That’s why the event will be staffed with officers from all police departments in the county to take information from families who have missing relatives, but never reported them. Residents from neighboring counties and Mexico were also invited to attend, and officials with the Mexican Consulate of San Diego will be available. Chaplains will be on hand to help families wade through stories that can be difficult to share.

Wagner said the presence of law enforcement officers shouldn’t deter families from coming forward.

“I do not want people to not come out of fear,” he said. “I want them to come because they have an expectation that sharing the information and the materials that they have will make a difference.”

It was DNA that eventually helped investigators identify Nellans’ body. Police are now investigating the death.

Estrada said DNA technology has drastically improved in recent years and relatives can easily leave a sample with help from a simple saliva swab.

Collected DNA will be checked against a database of DNA profiles of John and Jane Does that is maintained by the state’s Department of Justice. The agency works with other databases, so DNA that is submitted could match unidentified bodies found across the nation, Estrada explained.

“If you’re missing people, come down (to the Medical Examiner’s Office),” Nellans said. “These people can help you. They helped us.”