(CNN) — Deputies investigating the killing of a Texas man Monday morning weren’t able to find his daughter.

Authorities have issued an Amber Alert for 13-year-old Adriana Coronado, saying they believe the girl is missing and in danger.

“Investigators with the department have reason to believe that Adriana may have been with her father during the time of the homicide and that her welfare is in great danger at this time,” the Walker County Sheriff’s Office said Monday

The Amber Alert says she was last seen in the Houston suburb of Katy, Texas, early Saturday morning, two days before deputies began investigating the death of her father, Caesar Vladimir Coronado.

Detectives haven’t said what information led them to believe the teen’s safety could be at risk, and haven’t released details about her father’s slaying or identified a suspect in the case.

Adriana is 5 feet tall with brown eyes and is usually seen wearing black-framed glasses, authorities said.

“The Walker County Sheriff’s Office is asking for the public’s assistance in this matter,” Monday’s statement from the agency said, “and feel that time may very well be of the essence.”