HOUSTON — A federal appeals court has upheld the death sentence of a Corpus Christi man condemned for the 1998 fatal beating of his girlfriend's 4-year-old daughter.

In its ruling, the 5th U.S. Circuit Court of Appeals was critical of the Texas Court of Criminal Appeals for deciding earlier that attorneys at the 1999 trial of Richard Vasquez did an acceptable job during the trial's punishment phase.

"It was objectively unreasonable for the state court to conclude that Vasquez's trial counsel's performance was constitutionally sound," the New Orleans-based court said in a decision posted late Wednesday.

The federal judges, however, said Vasquez wasn't prejudiced by his attorney's "deficient performance," that his appeals lawyers didn't prove the lower court's prejudice determination was unreasonable and affirmed a Nueces County jury's decision that Vasquez should die.

Vasquez's appeals lawyers argued that his trial attorneys did little investigation to show jurors mitigating evidence that could have led them to decide he should get life in prison rather than death.

The attorneys said Vasquez's trial lawyers never spoke with his parents, didn't hire a mitigation specialist but instead hired an investigator with no experience in collecting mitigating evidence in capital murder cases.

According to the court opinion, "had Vasquez's trial attorneys undertaken even a rudimentary investigation of Vasquez's family and social history, they would have unearthed a frightening portrait of addiction and destruction."

Among the evidence not presented to jurors was that Vasquez's drug-addicted father taught his son how to use and sell heroin, took him along on drug runs and robberies, and that he began using marijuana at age 10 and was addicted to cocaine and heroin by age 13. His mother lived with a drug dealer who also provided him with drugs.

Vasquez was 18 when authorities said he fatally beat 4-year-old Miranda Lopez in the head because his girlfriend — the child's mother and also a drug addict — wouldn't tell him where she had hidden some cocaine. Evidence also showed the child had been severely sexually assaulted before she died and that cocaine levels in the child's blood were double the lethal amount for an adult.

Vasquez called 911 to report the girl unconscious and told paramedics she fell from a stool while brushing her teeth and hit her head on the floor. He became a suspect after the nature of her injuries became more clear.

In a second Texas death row case before the court, judges allowed 44-year-old Virgilio Maldonado, a Mexican national, to try to show he's mentally impaired and can't be executed for killing a man during a robbery in Houston 15 years ago.

Maldonado, from the western Mexican state of Michoacan, already had a record, including a bank robbery and another slaying, when he was condemned for the shooting death of Cruz Saucedo. Prosecutors said Saucedo was killed for marijuana, money and a gun.

The mental impairment issue previously was rejected by a state court after an evidentiary hearing. The federal appeals court now will hold its own hearing. The U.S. Supreme Court has ruled mentally impaired people can't be put to death.

The appeals court also rejected Maldonado's appeal of a lower court ruling refusing his claim that he improperly was denied legal protections entitled to foreign nationals under the Vienna Convention.