The Hernandez sisters climbed the tree outside their Las Vegas apartment every day, often until nightfall.
Its thick trunk, with low-hanging branches in all directions, made a perfect jungle gym for twins Diana and Adriana, 7, and Estela, 8.
That was a lifetime ago. Today the tree is gone. So is Diana.
On April 2, 1994, as their mother was paying the rent at the apartment complex near Maryland Parkway and Flamingo Road, the twins raced outside.
Diana sprinted ahead. That was the last time she was seen alive.
Her mother, Maria Samano, later found Diana's "Toys R Us" bag, neatly placed at her apartment door. An extensive search that day turned up no trace of the little girl in the Barney purple dinosaur T-shirt and white shorts adorned with blue fish.
The following day, Las Vegas police found her nude, lifeless body in a cardboard box in a complex trash bin. She had been raped, beaten and asphyxiated.
Fifteen long years - time her twin, Adriana Morales, now 25 and married, calls "torture" - would pass before an arrest.
"It kind of makes me angry ... that the system wasn't able to catch up (with him) so fast," she said. "It took 15 years of us suffering. Wondering whether the person I'm standing next to, did he do that to my sister? Or a family member? We didn't know who did it."
Cold case detectives in 2009 used new techniques to analyze DNA evidence and fingerprints to identify a man who lived in the same apartment building - a neighbor who even joined in the search effort - as Diana's killer.
Greg Wallen Jr., now 40, is in his third year in the Clark County Detention Center, awaiting a capital murder trial tentatively set to start on Nov. 26.
When contacted for this article, his attorneys would say little about their client, citing concern about compromising his case.
"Everything about his life is the case," public defender Norm Reed said. "When it's a death penalty case, their family, their work history, their drug history - all of that is the case."
It's unclear when the case will go to court. Earlier this month, Wallen's attorneys requested a delay, saying they need more time to prepare. Clark County District Judge Elissa Cadish will hear the motion on Monday.
A conviction may help bring some sense of closure to Samano and her daughters after years of frustration and grief.
But it also would offer solace to another family, that of a girl whose death in San Bernardino, Calif., has been unexplained since 1985.
Wallen knew that little girl, too.
27 YEARS AFTER DAUGHTER'S DEATH
On a brisk March day in Southern California, Carletta Doherty stood at the edge of a shallow drainage ditch, gazing down at the stagnant water and into her version of hell.
Twenty-seven years ago, on July 12, 1985, the pale body of a 6-year-old girl with gray eyes and brown shoulder-length hair was pulled from the ditch. She wore a lavender bathing suit with yellow and blue stripes. She was Doherty's daughter, Christina. Everyone called her Tina.
Tears streamed down Doherty's face at the sight of the ditch where Tina was found floating face-down in no more than 18 inches of water.
San Bernardino Homicide Sgt. Gary Robertson said all files regarding Tina's death were thrown away long ago because it was never categorized as a murder. The district attorney and coroner likewise have nothing left.
"It was a go-nowhere investigation," Robertson said.
But authorities did investigate. Police conducted interviews for at least 10 months. They established only that the girl with the ready smile was last seen near her home, about a mile from the ditch, a few hours before anyone noticed she was gone. Investigators theorized that she fell, was knocked unconscious and drowned.
There were no apparent signs of trauma, and no indication of sexual assault. Most of the key witnesses were neighborhood kids, considered too young to be reliable. Forensic science at the time provided little help.
In the end, police and prosecutors would determine that no murder was committed, though the San Bernardino County coroner wasn't so sure.
The coroner listed the cause of death as drowning, but didn't declare the manner of death a homicide or an accident. The coroner called it "undetermined."
Doherty calls it murder and says she believes now, more than ever, that the lanky boy who lived one street over killed her daughter.
Greg Wallen Jr. was 12 when Tina died.
"He has no soul," Doherty said. "He didn't in '85 and he doesn't now. He wasn't going to stop at my daughter. He was too evil."
Doherty has no illusions that Wallen will ever be tried for Tina's death, but she hopes justice will be served for Diana Hernandez - that Wallen will be made to answer to a higher power.
"He's got to face God one day," Doherty said.
'A LOT OF SICK STUFF HAPPENED'
Mike Martinez was 7 the last time he saw Wallen, who was in the back seat of a police car.
"I thought he was sitting in prison for the rest of his life," said Martinez, whose family still lives in the old neighborhood. "I thought they caught him for everything that he did, because a lot of sick stuff happened in this neighborhood when we were little."
The Wallen family moved away years ago, but the name still strikes a chilling chord for Martinez and his sister. Martinez vividly recalls Wallen threatening younger children with his pocketknife and forcing them to eat red ants. In his case, it was a live lizard.
"He would put his hands up against the bottom of my jaw and made me chew it," Martinez said. "He made me chew that thing up pretty good. I ended up spitting it out."
Martinez was 6 at the time. Wallen was a teenager in junior high school.
Sheri Holguin, Martinez's older sister by a year, said Wallen preyed on neighborhood girls, but left her alone because he feared her father.
Others lacked that protection.
Because Wallen was a juvenile, any criminal court records from his days in San Bernardino are sealed. But surviving police reports and records from several lawsuits describe a reign of terror on neighborhood girls:
On April 11, 1985, two sisters, ages 6 and 4, were playing in a neighbor's yard when Wallen lured them behind a fence with licorice. He asked them a question they didn't understand.
"He told me, 'Do you want to know what the F-word means,' " the elder girl said under oath in 1987.
The girls said he sexually assaulted them until a woman from the neighborhood interrupted, scaring him away.
Thirteen days later, Wallen told a 9-year-old girl that his sister had a new computer and wanted her to see it. But the sister wasn't there when they reached the Wallen home. In her deposition, also in 1987 but part of another lawsuit, the girl said Wallen asked if she knew what the word "f***" meant, and then said he would show her.
Wallen dragged the girl into the living room, where he choked her, she said.
"I acted like I fainted, and I guess he got scared, and then he ran into the kitchen," she said. "I tried to look out the side of my eye. I didn't see him, so I ran out."
The girl's mother testified that, "She came in screaming, crying. She had blood in her mouth, and she had, like, busted vessels all over her face. ... She told me Greg had choked her."
The families of the girls received small payments to settle their lawsuits against the Wallen family.
Police investigated, but it's unclear what, if anything, happened to Wallen.
Those who know him best - his parents, siblings and all but one family member contacted - declined to comment for this article, as did Wallen.
Martinez recalls that Wallen tried to divert investigators. When police interviewed Wallen, the youth admitted that he choked the girl, but also showed them facial wounds he claimed had come from a beating by her father.
Martinez said Wallen later told him, "I wanted them to think that he did it, so I got a brick and kept hitting myself in the face with the brick."
Seeing Martinez's puzzled look, Wallen laughed hysterically.
MOM KEEPS POLICE REPORTS
San Bernardino police could throw away files concerning Tina's death. She wasn't their daughter.
But, to this day, Carletta Doherty keeps about 700 pages of police reports, depositions and lawsuit papers in a yellow-tinged cardboard box that smells of cigarette smoke.
Those aging documents show that investigators focused on Wallen.
When they tried to establish his whereabouts the day Tina was found, Wallen told them a 21-year-old man, called the "neighborhood punk" in a deposition, had kidnapped Tina.
Police knew better.
"I then asked him if he actually made up the story, and he indicated by shaking his head that he had," an officer wrote. "I asked him if he made up the story because of some of the other neighborhood trouble. Greg told me that every time something happens in the neighborhood, they always put the blame on him."
His lie wasn't enough for an arrest, given the lack of evidence to support a homicide ruling. But it fueled suspicion.
Tina's father, Harold "Brian" Doherty, has since died, but in a 1987 lawsuit deposition he said that Bud Harter, a deputy coroner, told him "off the record" that he believed Tina was murdered.
Harter said "that she was struck with a large blunt object and she was choked and drowned and held under," Doherty testified. "And at the time, he didn't know for sure what he was talking about, but he said there was indications that she was trying to push herself up and that she was holding her breath."
Harter still works in the San Bernardino coroner's office. He did not respond to several interview requests.
An autopsy report in Carletta Doherty's files shows that Tina had abrasions above her right eye. That was said to support the theory that she hit her head and drowned.
But Doherty points to what isn't in the report. Tina was barefoot, but there were no apparent injuries on the soles of her feet.
How could she walk a mile on a 104-degree day without hurting her feet?
Carletta Doherty's mother-in-law, Goldie, had an explanation. According to police reports, she told of seeing a blond-haired boy wearing a backwards cap trying to get Tina onto the handlebars of a black beach cruiser only hours before her body was found.
The police report said Goldie could not identify the boy, but in a later deposition Carletta Doherty said it had to be Wallen. He was the only neighborhood boy of that description who had a bike like that.
Moreover, Wallen was seen that day on a street near the ditch, a police report said.
The place where the body was found is itself meaningful, Mike Martinez said.
"That just threw up a red flag for me," he said earlier this year. "Greg did it because those were, like, his spots he loved to go.''
The autopsy report also describes skin discoloration on Tina's neck. Her mother considers that significant, given Wallen's documented history of choking girls.
San Bernardino authorities abandoned their investigation when no manner of death could be established.
The girl's mother never stopped trying to get answers. She wrote letters to anyone she could think of, right up to President Ronald Reagan in 1986. She received a letter from the U.S. attorney general a month later, explaining that the president has no jurisdiction in such cases.
The Dohertys next took their fight for justice to the California attorney general, pleading for Wallen's arrest in 1988.
The response gave no hope.
"Even if we are to assume for the sake of argument that Christina's death was not accidental, there is absolutely no evidence that Greg Wallen was responsible for your daughter's death," the state attorney general's office responded. "The police department pursued every lead provided to them. Barring the receipt of new information or evidence that Christina was killed, no further investigation will be forthcoming."
Though Wallen was never charged in connection with Tina's death, his family's homeowner's insurance company paid the Dohertys $50,000 to settle a civil lawsuit alleging negligent supervision by his parents.
In court papers, Doherty's attorney accused the Wallens of being aware of their son's "propensity and capability for luring young minor females to be with him alone, and thereafter assault, batter and molest minor female children."
The Wallens did not admit liability, however.
A public record database indicates they left San Bernardino in 1990.
DAUGHTER DEFENDS SUSPECT
Heather Wallen's love for her father is permanent. She displays her adoration with a tattoo near her heart - Jesus on the cross, with Greg Wallen's name scrolled in ink.
"I've always been a daddy's girl," Heather said in an interview at the county courthouse in Pahrump more than a year ago.
She was 21 at the time, pregnant and shackled at the wrist and ankles. Her orange jail jumpsuit nearly matched her tangerine-colored hair.
Details of Greg Wallen's life after he dropped out of high school in 10th grade are difficult to pin down. Public records indicate he has lived in Mohave Valley, Ariz., Pahrump and Las Vegas as an adult. His daughter and police reports fill in some of the blanks.
Heather tells of a childhood damaged by drugs. Her father and mother, Susan, were addicts who abused Percocet, heroin and methamphetamine, she said.
Her grandparents became her primary caretakers when she was 3, a placement just steps ahead of state intervention.
Heather said her father was employed at a Walmart in Pahrump, and as a tile worker in Las Vegas. But, she said, her parents mostly lived off government assistance and her dad also "hustled."
"When he did drugs, he would go out for days and not come home," she said. "My mom would call him, and he wouldn't answer. He would finally come home when he was ready."
Susan Wallen, 39, is currently serving a prison sentence for drug dealing and child abuse, according to state records.
Though her father and mother were part-time parents at best, they did a world of harm to their three children.
Heather remembers a summer day at her grandfather's when she was 11. All three children watched her father put a loaded gun in his mouth and threaten to pull the trigger.
Since he was 20, Greg Wallen has been arrested more than a dozen times on charges ranging from failing to register as a sex offender, domestic violence and obtaining money under false pretenses. Few resulted in significant jail time; he served less than two years in prison.
In spite of that record, Heather maintains her father is innocent in the death of Diana Hernandez. She sobbed when speaking of the murder and rape charges against him, and said he never inappropriately touched her or her sister.
"You can't judge if you don't know," she said. "I know my dad is a good guy when he's sober.
"I wish he could have ... pulled himself out of the drugs," Heather Wallen added. "Because when he's on drugs, he's a lot different. When he's sober, he's like a dad."
Heather has struggled with her own addictions. She started using methamphetamine at 13, snorting it for the first time with her parents.
Despite Heather's assertions, her father has admitted to raping a child.
According to Nye County court records, in March 1993, Greg Wallen, then 20, agreed to plead guilty to reduced charges related to the rape of the 4-year-old daughter of a family friend.
But before he could be sentenced Wallen absconded to Las Vegas, moving his family downstairs from the apartment where Diana Hernandez lived.
Heather Wallen said she remembers "a little girl coming up missing" during that time, but not much more.
How investigators in the Diana Hernandez murder case failed to discover that Greg Wallen was wanted for child rape - which should have made him an instant prime suspect - is a mystery.
Police in 2009 said it was most likely because Wallen had not yet been convicted in Pahrump, though there was a pending warrant for his arrest.
Court records show that Nye County authorities caught up with Wallen in 1995. More than two years after he ran, he was back before a judge claiming to be a changed man.
"I would just like to say that I stand here, I'm waiting to take my punishment," Wallen is quoted as saying in a Nye County court document. "What I did was wrong. I'm very sorry for it, and I hope you will allow me another chance to prove to you that I've changed."
The judge sent him to the Lovelock Correctional Center, where he served less than two years of a three-year sentence.
This past summer, Heather Wallen pleaded guilty to burglary and grand larceny. She got four to 10 years in prison.
FAMILIES LINKED BY TRAGEDIES
Tina Doherty and Diana Hernandez never crossed paths. But because of Greg Wallen Jr., their lives are inextricably linked through years of anguish, fear and frustration.
"I don't know her, but we have a connection with her," Adriana Morales said of Doherty earlier this month as she and her sister visited the old apartment complex.
While their favorite climbing tree is gone, memories linger.
"She was really quiet, but she was so adventurous," Estela Hernandez said of Diana. "She always wanted to be out doing stuff. ... Playing in that tree."
The sisters hope Wallen will go to trial this month. But they say they'll never be prepared to hear again the heinous facts of their sister's death that will inevitably come out in court.
"My heart goes out to that family," Carletta Doherty said of the Hernandez's.
When Wallen goes to court, she plans to be there. She wants to look him in the eye so he'll know she never stopped chasing him these past three decades.
After all, she promised on the grave of her only daughter to never stop seeking the truth.
Doherty still remembers the last intimate moment they shared, the night before Tina died. She can almost see her daughter's gray eyes again just thinking about it.
"She told us, 'I don't ever want to leave you and daddy. I want to stay with you guys forever.' "
Contact reporter Antonio Planas at email@example.com or 702-383-4638.