A criminal sexual conduct conviction has been upheld for a St. Peter man who said he was denied a fair trial because the victim’s mother repeatedly spoke to the child in Spanish while the child was on the witness stand.

Luis Miguel Vargas, 26, was convicted of sexually assaulting a boy several times between 2003 and 2007. The boy was 10 years old when he took the stand as a witness at Vargas’ trial in August 2007.

The boy testified about three incidents, two where Vargas sexually touched him and one incident where he described anal sex. The jury found Vargas guilty of three counts of first-degree criminal sexual content and two counts of second-degree criminal sexual conduct.

District Court Judge Todd Westphal formally convicted Vargas for one count each of the first- and second-degree charges. During a hearing on Nov. 30, 2007, Westphal sentenced Vargas to 12 years in prison for the first-degree charge and 21 months in prison, consecutively, for the second-degree charge.

Vargas appealed both the convictions and the sentences.

He claimed the convictions should be overturned for three reasons. He said the boy’s mother, acting as a support person, spoke to him in Spanish three times during testimony, that Westphal should have cautioned the jury before allowing a social worker to say she believed the child was telling the truth and Westphal shouldn’t have allowed testimony about a 2006 exposure incident.

Vargas also claimed Westphal shouldn’t have issued consecutive sentences.

The Minnesota Court of Appeals ruled against all of Vargas’ claims, upholding both the convictions and the sentence.

Minnesota law permits a child abuse victim to have a parent or guardian present during testimony, the ruling said. Although Vargas claimed the mother could have been coaching the victim during his testimony, he didn’t provide any evidence of that.

Although the prosecutor should have told the boy’s mother not to interrupt, Vargas “has not established plain error affecting his substantial rights under the circumstances here,” the ruling said.

The appeals court also ruled it was within Westphal’s discretion to decide whether cautioning the jury would draw further attention to the Nicollet County social worker’s expert testimony that the boy was telling the truth. Evidence about the 2006 incident also was relevant, the ruling said.

The sentences were for two separate incidents, so they were justified, the ruling added.