One of the Kansas Bureau of Investigation’s top agents has joined the probe into the brutal stabbing death of Shannon Martin, a Kansas University honors student killed more than two years ago in Golfito, Costa Rica.

KBI homicide investigator Larry Thomas leaves Sunday for Costa Rica, where he’ll consult with Juan Carlos Arce, a lawyer representing the interests of Martin’s family.

“I won’t be intervening with the local investigation,” Thomas said Friday. “But I’ll observe and if I have any comments or recommendations or offers of assistance, I hope they’ll be considered as the case moves forward.”

Thomas, 49, is head of the KBI unit that specializes in reopening long-unsolved murder cases. He’s been a homicide investigator since 1977.

Thomas said his involvement in the case stemmed from regular conversations with Martin’s mother, Jeanette Stauffer of Topeka.

“She’s asked that we review the case file,” Thomas said.

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

“I’m very grateful to have been made a party in the case,” Stauffer said. “But I’m also very concerned that up until now, there were a lot of holes in the evidence that needed to be filled in. My attorney needs (Thomas) to do that.”

Though the case is more than 2 years old, Stauffer said some witnesses still had not been interviewed.

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“The case is not as solid as we’d like it to be,” Stauffer said. “I think it will be, but we’re not there yet.”

Thomas will be accompanied by Jesse Ybarra, a Topeka court translator. Ybarra speaks Spanish; Thomas does not.

Stauffer and her family are paying expenses for Thomas and Ybarra.

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

An autopsy showed Martin was stabbed 15 times in the early-morning hours of May 13, 2001. The next day, Cruz allegedly pawned a custom-made earring that belonged to Martin.

Martin, a former study-abroad student, was in Golfito to collect specimens for a biology project. Her body was found alongside an airport access road about 100 feet from her host family’s house.

Stauffer said she’d been told to expect a preliminary hearing sometime in July and a trial in August.

Thomas said he expected to be in Costa Rica about a week.

“At this point it’s hard to say how long I’ll be there,” he said. “I need to get down there first.”