For the first time in the two years since her daughter was stabbed to death in Costa Rica, Jeanette Stauffer says she has reason to believe the killers will be brought to justice.

“This is the first time I’ve gotten up in the morning and not asked myself, ‘OK, who do I have to call or e-mail today to make sure the investigation is moving forward?'” Stauffer said Friday during a telephone interview from her home in Topeka.

Stauffer’s daughter, Kansas University honors student Shannon Martin, was slain in the early morning of May 13, 2001, in Golfito, a Pacific port town.

Stauffer’s optimism stems from her talks with Larry Thomas, a Kansas Bureau of Investigation homicide investigator who, at her request, spent 10 days in Costa Rica assisting in the investigation. He was accompanied by Jesse Ybarra, a Topeka-based interpreter.

“We feel we opened up some new areas and avenues in the investigation,” said Ybarra, who was in Lawrence Friday. “We found one key witness, who had not been located until then, and some evidence was developed that had not been developed before.”

Ybarra, 55, said evidence may lead to charges being filed against one, two or three additional people now thought to have been at the crime scene.

Already, two men and a woman — Rafael Zumbado, Luis Alberto Castro and Kattia Cruz — are accused of attacking Martin after she left a Golfito nightclub.

Ybarra said forensic evidence — a blood stain — indicated at least one other person was involved in the attack.

Martin’s body was found alongside an airport access road about 100 feet from her host family’s house. She had been stabbed 15 times.

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Martin, an exchange student, was in Golfito collecting fern specimens for her senior research project.

Thomas, 49, could not be reached for comment.

Ybarra said the case was “a very big deal” in Golfito, noting that he and Thomas were often told that the town was far from crime-free but that a young woman like Martin should not have been in danger.

He added, “And for (the victim) to be a young American girl is unheard of.”

Ybarra said he was confident the killers would be successfully prosecuted.

“There is a lot that I cannot talk about at this point, but the evidence is there,” he said. “They have a strong case. They’re doing a good job.”

Last month, Costa Rican officials agreed to let Stauffer participate in legal proceedings surrounding the case. Stauffer, in turn, hired an attorney, Juan Carlos Arce, and asked Thomas to review the evidence.

Stauffer said she expected a preliminary hearing date to be announced in August.

“The investigation is still going on,” she said. “And now, because of Larry and Jesse, I can say it’s going to be a very thorough investigation.”