Yesenia Soto described her late sister as gregarious and someone who never let people get the best of her.
"She was really happy, always smiling," Yesenia, 16, said of younger sister Diana Soto, 14. "Sometimes she would want to cry, but she would hold it in. She didn't want anybody to see her upset."
Details released Wednesday by Las Vegas police said that Diana, an eighth-grader at Robison Middle School, fought until the very end of her life.
Her body was discovered by police early Sunday in a parking lot of a northeast valley day care about a mile from her home. She was wearing black soccer shorts and a red tank top, both of which had been partially pulled down, according to the police report.
Police arrested Juan Rivera, 19, on Monday in connection with her slaying.
Rivera, who had several scratches on his face when questioned by police, admitted he saw Diana the night before her body was found, according to the report.
Police identified her on Monday when they connected her to a missing person's report.
Rivera, who was dating Yesenia and fathered their infant daughter, lived with the Soto sisters in a mobile home near Washington Avenue and Lamb Boulevard.
Yesenia said she was devastated when she learned her boyfriend had been arrested in connection with her sister's murder.
"When I found out he did it, all the love I had for him went away," she said Wednesday on the patio of her home, a few feet from a makeshift memorial for Diana.
Police interviewed Rivera on Monday, and he agreed to take a Concealed Information Test, which is similar to a polygraph test. The report stated that Rivera failed the test.
Police later learned that Diana had asked Rivera to take her to a friend's house in North Las Vegas on Saturday night, according to the report, and that Rivera and Diana had been arguing about decisions she was making in her life.
She scratched his throat and chest, the report stated, and after an angry Rivera began choking her, Diana fought back and scratched his left cheek and right eye.
Rivera said he strangled her for about a minute, "until blood came from her nose and she no longer moved," according to the report.
He took Diana's cell phone and sent out various texts to a friend to make it seem as if she was still coming over, according to the report. Then he drove around until he saw a vacant parking lot and dumped her body near a tree and block wall, the report stated.
He then drove home, took her cell phone, broke it in half and threw it in a neighbor's trash can before he went to sleep, according to police.
The Clark County coroner's office has not released the cause and manner of Diana's death.
Yolanda Regalado-Lucero, an aunt of the Soto sisters who arrived from Juarez, Mexico, to be with Yesenia, described Diana as a very kind girl. Speaking in Spanish, Regalado-Lucero said her fondest memories of Diana came when she would ask her to make traditional Mexican dishes such as tacos and gorditas.
Rivera is being held at the Clark County Detention Center without bail on several charges, including murder, sexual assault and robbery. A court appearance for him is set for today .
Rivera denied sexually assaulting Diana, according to the report, and he provided a DNA sample to police.
Yesenia said Rivera was never physically violent or verbally abusive toward her, but that he and Diana did not get along.
She said that Diana was a talented soccer forward and that the two of them played soccer together several times a week. Yesenia also said her sister dreamed about one day becoming a pediatrician because she loved children.
Diana will most likely be buried in Juarez, Yesenia said, near the border and next to her father, who died a decade ago.
Contact reporter Antonio Planas at aplanas@ reviewjournal.com or 702-383-4638.