Jury selection in the trial of a teen accused of killing her stepmother won’t begin until Tuesday if it begins at all.

On Friday, defense attorney Marshal Sanders presented an evaluation from psychiatrist Billy Fox of Clinton saying Tyla Vega, 15, 100 Jones Road, is not mentally capable of standing trial for murder in the shooting death of her 32-year-old stepmother.

The trial had been scheduled to begin Monday in Warren County Circuit Court with Judge Isadore Patrick presiding.

“I can tell you based on what I see and speaking with Dr. Fox that she is seriously traumatized,” Sanders said.

Patrick will hear testimony from Fox at 9 a.m. Monday and issue a ruling on if the trial can proceed.

The defense had requested the evaluation in February but it was not turned over to the prosecution until Friday morning, District Attorney Ricky Smith said.

“We received it not just at the eleventh hour but at the eleventh hour and 59th minute,” Smith said.

Tyla Vega is accused of shooting Michelle Vega in the face May 10, 2011. Tyla Vega, then 14, was seen driving away from the family’s home minutes before Michelle Vega’s body was found. She was arrested in Greenville after a six-day, multicounty search.

On Monday before the hearing, Patrick is expected to rule on the admissibility of statements Tyla Vega made to Warren County deputies.

Sanders argued Friday that Tyla Vega did not understand her Miranda rights because of her age.

Investigator Stacy Rollison testified that she interviewed Tyla Vega for about three hours May 9, 2011. During the interrogation, Tyla Vega nodded but did not verbally acknowledge that she understood her rights, Rollison said.

Sanders argued Tyla Vega did not nod in the videotaped interview, and Patrick was expected to analyze the video this weekend.

On standardized tests, Tyla Vega’s scores showed above-average verbal skills for her age, said Dr. Michael Winters who was principal at Vicksburg Junior High School while she was a student there.

Tyla Vega scored proficient on her state tests in fifth, sixth and seventh grades, and her scores were “significantly higher” than the state average, Winters said. Tyla Vega was in the eighth grade when the shooting happened.

If convicted, Tyla Vega will be granted an automatic appeal because of a U.S. Supreme Court ruling this summer. In a 5-4 ruling June 25, the court struck down laws in Mississippi and 28 other states that impose mandatory life-without-parole sentences on convicted juvenile murder defendants.

Mississippi law requires that juveniles 13 and older be tried as adults if they are accused of crimes such as murder and those that include the use or attempted use of a deadly weapon.