(Courtesy of Wilkins Family)

By Maria Nikias and Sabina Ghebremedhin

Authorities are trying to piece together details in the puzzling death of  a 25-year-old Malibu, Calif. graphic designer found dead in garage of her parents' home over the weekend.

The body of Katie Wilkins, 25, was discovered Saturday evening by her brother, according to the Los Angeles County Sheriff's Department.  She was pronounced dead at the scene.  And her car, a silver BMW, was missing. For a time, the death was being investigated as a homicide.

But after an autopsy today, police said they do not believe foul play was involved in Wilkins' death, though many questions remain and according to a statement by the sheriff's department, "The investigation is on-going."

Steve Wilkins, Katie Wilkins' brother, said the family is desperate for information about what led to her death.

Detectives are searching for anyone who may have been with Wilkins prior to her death, and they are continuing to look for her car,  according to Lt. Tim O'Quinn, one of the lead detectives on the case.

The final cause of Wilkins' death will not be determined until after toxicology tests are completed, authorities said.

Wilkins' parents left town Friday on an out-of-state trip.  Saturday her brother went to check on her, at the house where she lived with her parents, and found her lying on the garage floor.

"I put my hand to her wrist and it was really cold," Steve Wilkins told ABC News affiliate KABC. "All of a sudden, a bunch of questions come through, what happened? How could she be left like this? Was she alone?"

The family's home is on a cul-de-sac in a quiet, affluent neighborhood in the Malibu Hills. Family members say the windows and doors in the house were all locked when Wilkins was found, including the front door. Yet, her car, a silver 1998 BMW Z3 with red interior and license plate number 4AMN588, was missing.  And the family dog was found wandering the neighborhood.

Family members said there were no obvious signs of trauma to her body.

"Well I think as you know, we lost our daughter the other night" said Rob Wilkins, the victim's father, told KABC. "They're looking for the car, so we're just trying to do what we can to figure out what happened. "

Family members said Wilkins was a well-liked and happy person. After graduating from the Art Institute of California, Orange County, last year, she started her own freelance graphic design business called Katie Wilkins Design.

"It just doesn't make any sense. I just couldn't figure out what in the heck could have happened?" Diane Wilkins, the victim's mother, told ABC7. "It just doesn't add up at all.  It's gut wrenching, I mean, it's very hard."

Anyone with information is encouraged to contact the Los Angeles County Sheriff's Department Homicide Bureau at 323-890-5500.