Was 2005 murder conviction based on junk science?

Carmen Mejia was charged with murder in 2005 after a severely burned 10-month-old baby died. Mejia gave social workers and investigators different stories about what happened. Since the trial, a child who was in the home at the time of the incident said they were the one who turned on the faucet when the baby was in the bathtub. Now, Mejia is seeking a new trial.