Danyel was last seen inside her family's residence in the 1900 block of Manzanita Way in West Sacramento, California on November 2, 1985. Her mother, Cynthia Sparpana, was found deceased by police inside the residence on November 5; she had been dead for two or three days. Cynthia was the victim of a violent homicide; she had been beaten and shot in the back of the head. None of Danyel's belongings were missing from their home. She has never been heard from again.

Lionel Ernest Tholmer Jr. was named as the prime suspect in the Sparpanas' cases shortly afterwards. He had been an acquaintance and sometime lover of Cynthia's. Authorities believed that Tholmer was also responsible for the November 1985 slaying of California resident John B. Meadows. Meadows was Tholmer's ex-wife's stepfather and investigators believe Tholmer wanted to frame him for Cynthia's murder. Tholmer resided in Georgia, but returned to the Sacremento area to work at McClellan Air Force Base in the mid-1980s. He was convicted of Meadows's murder in 1987 and was serving a life sentence for that when he was charged with Cynthia and Danyel's murders.

At his trial, Tholmer's lawyers argued that he was innocent of Cynthia's murder and that Danyel had not been murdered at all. There have been unconfirmed sightings of her since her mother's death. Tholmer was convicted of the Sparpanas' murders in November 1992. Danyel's remains have never been located. Foul play is suspected in her case due to the circumstances involved.

Some agencies may list November 5, 1985, the date her mother's body was found, as the date of Danyel's disappearance.