Fort Worth dentist arrested, accused of giving 4‑year‑old lethal doses of sedatives, police say

A Fort Worth dentist is behind bars, accused of administering a lethal dose of sedatives that killed a 4‑year‑old girl during a routine procedure, authorities said.

Dr. Chrishelle Hemphill, 48, was arrested on Wednesday, according to newly released arrest records. Investigators say Hemphill gave 4‑year‑old Aithana Arriaga an oral liquid solution of Meperidine – also known as Demerol – along with two additional sedatives and nitrous oxide.

According to the arrest warrant, the April 1 appointment began as a routine tongue‑tie procedure at Cuddle Kids Dental Care, the Sycamore School Road clinic owned by Hemphill. Investigators say Aithana was given multiple sedatives before she went into distress.

Investigators say Hemphill was the only one who administered the drugs to Aithana. 

Detectives say Hemphill began chest compressions when Aithana became unresponsive. A second dentist, who had been on lunch break, stepped in and continued CPR until medics arrived.

The medical examiner told investigators that "the amount of meperidine found in Aithana's system would have been high for an adult and that the medication was given to her twice (double-dosed)."  

The Tarrant County Medical Examiner ruled Aithana's death as Meperidine toxicity. 

Hemphill is now facing criminal charges as the investigation continues.

CBS News Texas will provide updates as more information becomes available.