Mikelle was last seen riding her bicycle near her family's residence in Mesa, Arizona on January 2, 1999. Mikelle and her younger sister thought they heard an ice cream truck's music in the distance and asked their mother for money. Mikelle and her sister waited for the truck near Toltec Street and El Moro Avenue at approximately 5:50 p.m. Her sister became cold and returned to the family's home for a coat. Their mother sent her back for Mikelle, but she had disappeared. Mikelle's bicycle and her two quarters were found near the street where she had been standing. The bicycle was not at the corner, but partially back towards the house. It was lying on its side with the wheel still spinning. Mikelle and her sister had been separated for only about ninety seconds.

Authorities searched the entire area near Mikelle's family's home, but no evidence pertaining to her whereabouts was found. Search dogs lost her scent after only a few feet, suggesting she was placed into a vehicle and driven away. Authorities were unable to confirm if an ice cream truck was in the area at the time of her disappearance, but all ice cream vendors in the area were cleared of involvement in Mikelle's case. Known sex offenders in the vicinity were also cleared of any connection to Mikelle.

There have been many false leads in Mikelle's case. On January 9, police dug up what appeared to be a freshly-dug grave outside of Mesa. They found nothing. Two witnesses were put under hypnosis in hopes that they would remember something, but nothing came of that. A copper-colored jeep was reportedly spotted near Mikelle's home at the time she was last seen, but when its driver was located he was ruled out as a suspect and he had seen nothing usual. Houses in the neighborhood were searched with the consent of their owners, but to no avail. Only one homeowner refused to permit a search; he is not considered a suspect. On March 10, 1999, a man reportedly tried to abduct two girls, a 10-year-old and an 11-year-old, from a schoolyard. Police thought the incident might have been connected to Mikelle's case, but the "abduction" was revealed to be a hoax.

Investigators have released sketches of two possible suspects in Mikelle's disappearance. Both images are posted below this case summary. The sketches are not being widely publicized since authorities are not certain if the men are connected to her case.

Mikelle's father believes he knows who was reponsible for his daughter's apparent abduction. The man, Dee Blalock, lived two blocks from the Mikelle home in 1999. He had prior convictions for sex offenses in three states and was registered as a sex offender. In 2001, he was convicting of raping a neighbor and trying to kill her. He is presently serving a fifteen-and-a-half-year sentence in an Arizona prison. Blalock denies any involvement in the case, and his wife provided him an alibi for the time Mikelle disappeared. On the fifth anniversary of Mikelle's disappearance, her family held a funeral for her with an empty casket. Her family now lives in Gilbert, Arizona. They believe Mikelle was murdered shortly after her disappearance. No charges have been filed against anyone in her case.

Mikelle is described an intelligent, artistic, sociable person and an honor student. She played the clarinet and was a member of her school's student council at the time of her disappearance. She wanted to become an animator when she grew up. Her favorite color is purple and she has two younger sisters and a younger brother. There are few leads in Mikelle's disappearance and her case remains unsolved.

Above: Sketches of possible suspects in Biggs's disappearance