AUGUSTA, Ga. (AP) — Most missing person reports concern runaway teens who don't stray far, but sometimes, like in two missing person cases in Augusta last year, the cases end tragically.

Remains found buried in a shallow grave earlier this month were determined to be LaTania Janell Carwell. Sometime on the night of April 16, investigators believe the teen was killed by her stepfather, Leon Tripp. April 17th would have been her 16th birthday.

Julian Williams, 23, was last seen waiting for a cab in the early morning hours of March 26, 2017, in front of his Broad Street apartment building. His body was found April 26, 2017, buried behind an abandoned trailer on Spider Web Road in Beech Island. Two men have been charged: Antonio Deaunte Simpkins with murder and kidnapping, and Steven Ray Jackson with kidnapping and failing to report a crime.

Janell and Williams were two of 40 people reported missing in Richmond, Columbia and Aiken counties since 22-year-old Mary Radford disappeared March 28, 1974. Nine have been found dead; the rest are still missing.

Most missing persons, however, are runaways and most of them return home, said Richmond County sheriff's Sgt. Ron Sylvester. For the most part, runaways stay in the area, he said. Children in state custody, through the Department of Family and Children Services, must be reported as missing if they leave home without permission, Sylvester said. He has one open missing person case with a teen he knows is in New York with relatives, but the family won't cooperate and he can't close the case.

Audrey Genzer, a mentally disabled 27-year-old, was reported missing on a recent Sunday morning from her Milledgeville Road home. Officers found her about 24 hours later drinking coffee at Starbucks at Augusta Mall.

When adults go missing, Sylvester said he keeps running records' checks to see whether they turn up, but sometimes it's like they have fallen off the earth. A number of people with mental disabilities have been reported as missing but mental health facilities won't release information about patients, Sylvester said. When an elderly resident goes missing, that person is generally found if the disappearance is reported quickly, Sylvester said. He remembers one case, however, when the victim wasn't found in time. Elizabeth Bert, 85, who suffered from Alzheimer's disease, was found dead on Fourth of July weekend in 2009.

Sometimes years have passed before a missing person's remains have been found. Tiffany Nelson was 9 when she disappeared June 6, 1994, in Augusta. Her remains were found in Burke County in 2005, and she was identified through DNA testing. No one has been charged in her case.

Tiffany was last seen at a convenience store near her home. Dannette and Jeanette Millbrooks, 15-year-old twins, disappeared March 18, 1990. They had visited a convenience store near their home. A billboard announcing an $8,000 reward for information was put up last week.

Before those disappearances, 8-year-old Tiwana Cheatham went missing Aug. 11, 1989. She was also last seen at a convenience store.

District Attorney Natalie Paine said there's no single common missing person case. While most are runaways who are located quickly, a few are people in danger and because of that, each case has to be treated carefully. It's also critically important for people to be truthful about the missing person, she said.

Paine said she thinks there needs to a better procedure for collecting dental records of the missing person and DNA samples from relatives in cases where bodies are found. If the information was put in a national database, it could help identify bodies found elsewhere, she said. Carwell's remains were identified through dental records, and Tiffany was identified through family members' DNA.

Even if a missing person is considered just a runaway, a teen on the street can get into trouble, Paine said.

Teens can easily get involved with people eager to take advantage of them. For example, a teen who left home and moved into an adult friend's home was soon being pimped out. The 16-year-old ended up in Augusta, where Charlie Castillo and two women set up an online account to lure men into having sex with her for money that the adults kept. Castillo was convicted in federal court in 2014 and sentenced to 21 years in prison.

Not knowing what happened to a missing person leaves the family members in pain every day, said the mother of a woman who has yet to be found. "The worst part of all is not knowing," said Janice Phelps, whose 25-year-old daughter, Angel Phelps, disappeared Nov. 25, 2011. It's been so long she can't believe her daughter wouldn't have contacted someone in the family, but she still wishes for a miracle. She keeps her landline with the same telephone number that she had in 2011 in case Angel calls.

"You hope and pray and you don't want to think that someone killed your child," Phelps said. She just has to get up every day and go on with life and ask the Lord for help. "Without prayer, I don't know what I would do."