A 1986 rape and murder case of a 12-year-old in Tacoma, Washington, came to a close with the help of advanced DNA technology and the suspect was arraigned Monday.

Michella Welch, a sixth grader, was babysitting her siblings on March 26, 1986, in Puget Park in North Tacoma. She briefly went home at 11 a.m. local time (2 p.m. EDT) to pick up some sandwiches. She was never seen again.

Authorities believe that she came back to the park and went looking for her siblings who had gone to use a restroom nearby. When Welch hadn’t returned even after three hours, her siblings grew concerned. They noticed her bike and the food but never located Welch.

Nicole Eby, Welch's younger sister recalled going to look for their sister in vain. "We call it a 'yoo hoo.’ And we yoohooed and yoohooed. We didn't hear her." Eventually, the family took help from law enforcement to find the missing girl.

Welch’s body was found by a search dog just before 11 p.m. local time (2 a.m. EDT) the same night. There was evidence of the victim being sexually abused and murdered by blunt force trauma to the head.

Although DNA samples were collected from the crime scene and a number of witness statements were taken by the police, none of it led anywhere and the case turned cold. The case was reopened in 2006 when a DNA profile was compiled but it did not match anyone from the database, ABC News reported. 

Pierce County Prosecutor Mark Lindquist said that only recently Tacoma Police detectives worked with genetic genealogists who used DNA technology to track the potential suspect's family members and later cross-referenced the information with traditional genealogy to make a family tree from information on public websites. At the end, they narrowed down on two brothers from that time period, who became the prime suspects for the police.

The detectives started keeping tabs on Gary Hartman, 66, one of the suspects, from June 4. During their stakeout, they collected a discarded paper napkin that Hartman had used at a restaurant where he had gone to have breakfast with a co-worker and submitted it to the state crime lab for testing. After a match was established between the DNA on the napkin and the DNA from 1986, Hartman was arrested on June 20 and charged with first-degree murder and first-degree rape in the death of Welch.

Barbara Leonard told NBC affiliate King5 what it felt like to receive the news that her daughter’s case was close to being solved after 32 years.

"Chief Ramsdell said 'Are you sitting down?' I had a chair right there so I said. 'Yes.' He said, 'We have apprehended the person we feel is responsible for Michella's murder.' I didn't know whether to laugh or cry," said Leonard.

Although the victim’s family has never expressed anger or resentment toward the suspect, they are determined on getting justice for Welch.

“There are consequences to those actions that we do in life," said Angela Velazquez, Welch's other sister. "That if you are not held accountable it changes you into a different person and you think you are above the law."

DNA A 1986 rape and murder case of a 12-year-old in Tacoma, Washington, came to a close with the help of advanced DNA technology. In this photo, a member (L) of the Argentine Team of Forensic Anthropology (EAAF) takes a blood sample for DNA testing from a man with a missing relative, who disappeared during his journey through Mexico to reach the U.S., at the town of the Ermita outside Tegucigalpa, Honduras Aug. 11, 2015. Photo: REUTERS/Jorge Cabrera