TAMPA (WFLA) – A murder trial is underway in Costa Rica for the man accused of killing a South Florida woman on vacation.

Carla Stefaniak, who lived in the bay area for more than a decade, was found dead in a shallow grave not far from her Airbnb in December 2018.

Stefaniak’s family knows that there’s no outcome that will bring their beloved daughter and sister back but they’re fighting to make sure this never happens to anyone like her again.

It’s been more than a year but the pain is still very real, for Carla Stefaniak’s younger brother, Mario Caicedo.

“We don’t want a monster in the streets,” Caicedo said. “We were really close and it just hurts a lot to have lost her.”

On Monday, the trial began for Bismarck Espinosa Martinez. Authorities say the former Airbnb security guard killed Stefaniak after she returned alone to the apartment she rented through Airbnb.

But Stefaniak’s family and their attorneys have reason to believe he wasn’t the only one involved.

“She fought really hard according to the forensics and we just don’t believe that nobody heard or saw anything,” Caicedo said.

Prosecutors previously upgraded the charges from second-degree to first-degree murder, after pressure from Stefaniak’s family.

If convicted Espinosa-Martinez faces up to 66 years in prison.

Following her death, Stefaniak’s family is also suing Airbnb, claiming the company didn’t do a background check on the suspect who was in Costa Rica illegally and failed to warn guests about safety concerns in that country from the U.S. State Department.

Airbnb mentioned nothing about being sued after 8 On Your Side requested a statement concerning the lawsuit. 

An Airbnb spokesperson said in the statement: 

Our hearts are broken for Carla’s family, friends, and loved ones. We reached out to provide support to them during this unimaginably difficult time. We have also been in contact with Costa Rican and American law enforcement authorities, and we are standing by to support their investigation, as justice must be served quickly. The Villa Le Mas has been removed from the platform.