JACKSONVILLE, Fla. -

Lawyers for 13-year-old murder suspect Cristian Fernandez are asking the judge to re-depose one of the Jacksonville Sheriff's Office detectives involved in the case.

A motion filed in court says the detective wasn't prepared for the deposition, and the public defender didn't ask the right questions.

Fernandez' new lawyers want to know who had contact with the boy before he was brought in for questioning, and they have concerns about the consent his mother gave to police to question him.

Fernandez is accused of beating his 2-year-old half brother to death last year.

His mother, Biannela Susana, pleaded guilty in March to a charge of aggravated manslaughter in the toddler's death.

A trial date for Fernandez on the murder charge is set for Sept. 10.

He also has a trial set for June 25 on a sexual assault charge.