The Bradenton Police Department was filled this afternoon with people hoping to be a match for a little girl battling cancer.

Gianna Lesselroth, 3, has been battling leukemia since she was 4 months old.

She was in remission until Mothers Day. However, this time the cancer came back with a vengeance. It's in her brain and her nervous system. Gianna's now in a Boston hospital with her family undergoing treatment.

“She knows exactly what she wants," said mother Marissa Lesselroth. "She is defiantly a fighter.”

A bone marrow transplant could help save Gianna’s life. That’s why hundreds of people came to the Bradenton Police Department Tuesday to find out if they are a match.

Officer Emily Parsons with Bradenton Police heard about Gianna's story and put together the bone marrow drive.

“I just felt the need to do something to help out,” said Parsons.

Tara Poulton is one of the residents who came out to see if she's a match.

“I have never done this before, but I am a parent and if my child needed this I would want the community to come out for her,” said Poulton.

Poulton rubbed the inside of her cheek with four swabs and hoped for the best.

"Absolutely worth it and I hope it makes a difference," Poulton said.

Lesselroth says people like Tara could save her daughter's life.

“We are extremely grateful and thankful,” she said.

The Bradenton Police Department said over 500 people showed up to see if they are a bone marrow match, so many that they actually ran out of the swab kits. You can help by visiting Gianna’s Facebook page.