When her brothers were ready to go home, Lesia wasn't. They started walking without her. Lesia eventually followed and she was last spotted walking alone on Creek Bend Street towards home.
That was the last time anyone saw Lesia alive.
The little girl's death is one of the highest-profile unsolved murders in Montgomery County. Tips still come into the sheriff's office. Now, for the first time, detectives are sharing new details about what Lesia was wearing when her lifeless body was found.
"For me, the hard part is the victim. You know? Just a 12-year-old girl," said Detective Terance Greenwood, standing over a box of binders filled with information about Jackson's case.
"As a parent, when your child is missing, you can't find her, you have no idea where she's at, what happened to her, what's going on with her. It makes you want to solve this, at whatever expense," Greenwood said.
EXTRA INFO: this is the missing person’s report filed in Montgomery Co 3 days after Lesia Jackson disappeared. No such thing as an #AmberAlert in 1979. Lesia’s body was found another 3 days after the report was taken. #abc13 #coldcase pic.twitter.com/1esdea3NUJ— Courtney Fischer (@CourtneyABC13) February 15, 2018
The day after Lesia disappeared, her brother found her tortoiseshell eyeglasses at the intersection of Creekwood and Deep Forest, in the same subdivision where she was walking.
Reports say six days after she went missing, an oilfield worker found Lesia's naked body in the woods along Exxon Road, about a half mile from the lake.
Lesia had been raped and strangled. There were tire tracks nearby, tracks investigators believe are from the killer's car. Lesia's bright blue bikini was laid out near her shredded little t-shirt.
BLUE BIKINI found next to Lesia’s naked body has been tested and retested for the killer’s DNA several times since it was found in 1979. Results have been inconclusive. #abc13 #coldcase pic.twitter.com/iRas6cXNg1— Courtney Fischer (@CourtneyABC13) February 15, 2018
"The photos are very gruesome," said Detective Kenneth Bivens, with MCSO.
For the first time, detectives are making public a picture of the gold butterfly necklace Lesia was found wearing. The day she was abducted, she had on a matching ring. That ring was never found. Detectives kept that detail private all these years, hoping the killer may have it, connecting him to Lesia's murder.
Over nearly 40 years, detectives have chased hundreds of leads. The most recent tip came in a couple years ago.
"A guy called in about a white station wagon driving erratically through the neighborhood," Bivens said.
That tip turned into nothing.
Bivens spent much of 2017 pulling old tax records of people who lived near Lesia's family in 1979.
"I'd spend a few hours and get peoples' information, who lived in what house, then look at criminal histories in that area," Bivens said.
Time is running out. Simply put: witnesses and old suspects are dying.
"We have a little 12-year-old who has been murdered and we need to find out who did it," Greenwood said.
Lesia's mother and brothers have since moved away from Texas. We talked to one of her brothers about the case. Family members declined to do an interview saying it's just too painful to talk about what happened that day. That brother says Lesia's family forgave the killer many years ago, saying it's the only way they could keep living.