When the jury went to determine Ricardo Gallegos's fate on robbery charges, 13 people--not the usual 12--walked into the deliberation room.

One of the jurors, Luis Escobedo, was accompanied by a translator, following a judge's ruling this fall that potential jurors in Dona Ana County cannot be eliminated simply because they do not speak English.

Now, with no legal precedent for guidance, prosecutors in this heavily Hispanic county along the Mexican border are scrambling to answer questions like: Should each non-English-speaking juror have his or her own translator? Are translators even allowed into jury deliberations?

"There are so many questions created by the decision that for us to fumble to figure out the procedure, we're sure to make an error and have to try these cases again," said Susana Martinez, district attorney in Dona Ana County, an area of cotton and chili fields and pecan groves.

The county, with a population of 167,500, is 58 percent Hispanic. In the 1990 census, 17.9 percent of residents said they spoke Spanish and limited or no English.

While it has become common for deaf jurors to use sign-language translators, Nancy Festinger, former president of the National Association for Judiciary Interpreters and Translators in New York, said she knows of no state besides New Mexico where non-English-speakers are serving on juries.

Similarly, Larry Dodge, founder of the Fully Informed Jury Association, a nonprofit group in Helmville, Mont., that educates Americans about their rights as jurors, said he is not aware of any other state with such a provision. He welcomed the ruling.

"If you're talking about a jury of your peers, this is it," Dodge said. "We think a random cross-section of the community is the right way to run a jury trial."

Court administrators across New Mexico are awaiting a ruling by the state Supreme Court to see if they, too, need to change their procedures.

Until now, some New Mexico counties have automatically excluded non-English-speakers; others have offered translators, but have excused anyone who asked to be excluded on the basis of language. It is believed that only a couple of non-English-speaking jurors have actually served in the past, both in Santa Fe.

Dona Ana County's practice of automatically excluding non-English-speakers was challenged last year by criminal defense attorney Herman Chico Gallegos, who succeeded on his third try.

In October, state District Judge Robert E. Robles threw out a jury pool of several hundred, saying it had been illegally impaneled because non-English-speakers were excluded.

Robles cited the 1911 New Mexico constitution, which says residents cannot be restricted from sitting on juries on account of an "inability to speak, read or write the English or Spanish languages."

One question the state Supreme Court may now have to clarify is whether excusing someone who asks to be excused amounts to restricting that person's rights.

In Dona Ana County, at least 15 trials were put on hold until a new jury pool was assembled Dec. 1. Of about 600 prospective jurors in the new pool, 19 speak only Spanish.

Ricardo Gallegos, 21, and his co-defendant were the first whose trial was affected by the ruling, and both were acquitted. Gallegos, who speaks both Spanish and English, said he had no problem with Escobedo listening to a translation through headphones.

As for Escobedo, he said it was satisfying to be able to serve on a jury. He has been a U.S. citizen for nearly 30 years.

"I understood perfectly well," said the 74-year-old retired mechanic from the town of La Union. "Everything went well with the interpreter."

Although there have been no complaints so far, court officials said numerous problems are bound to crop up. For one thing, there aren't enough interpreters in the area to serve the six-courtroom courthouse.

And then there is the expense. State-certified interpreters, most of whom speak Spanish or Navajo, are paid $30 an hour, said Fern Goodman, general counsel for the state Administrative Office of the Courts.

For translators who speak languages uncommon here, it will cost much more. The court system had arranged to bring in an interpreter from California for a man who spoke an Indian dialect, and it would have cost taxpayers $180 an hour plus expenses if the juror had not been excused for health reasons.

Another problem, Martinez said, is the possibility of mistranslation. She said in the past, both she and a Spanish-speaking judge have disagreed with an interpreter for a witness or a defendant.

Which raises another question: Could one translator work for a juror as well as a defendant or a witness in the same trial?

"It's like a Rubik's Cube," said Sandra O. Caldwell, an interpreter at the courthouse. "The combinations are endless."