One of the victims in Monday’s tragic shooting at Boise Towne Square mall was identified by family and friends early Tuesday.

Jo Acker, 26, was working security at the mall during the time of the shooting, her friend Dominique Cairistiona said.

Boise Police responded Monday just after 2 p.m. to reports of gunfire and at least one person wounded at Boise Towne Square. When officers arrived, they encountered a person matching the description of the shooting suspect and an exchange of gunfire followed, according to Boise Police Chief Brian Lee. The incident left three dead including the shooting suspect, Boise Police announced Tuesday. Four others were injured.

The other shooting victim was identified as 49-year-old Roberto Padilla Arguelles, a resident of Rupert, according to the Ada County Coroner’s Office.

Acker identified as a transgender woman, according to her Facebook page. She was born in Seattle and grew up in both Colorado Springs, Colorado, and Boise. Additionally, Acker previously served as a forward observer in the U.S. Army, Cairistiona said.

In a post on Facebook, Acker’s family asked people to respect their privacy at this time. In a statement to the media, they called Acker “a hero” and “the type of person that always wanted to help people.” They said her heroics saved lives, that she was loved by those who knew her, and she “will be greatly missed.”

Cairistiona said that Acker was selfless and would do anything for friends, family and strangers in need.

“I have very confusing emotions right now. On one hand I’m upset that she was selfless and put herself in danger — but on the other hand I would expect nothing less of her,” Cairistiona said. “That’s exactly her character, to do whatever she could to help as many people as she could.”

Shiloh Ren, who has been friends with Acker since high school, said Acker will be remembered as the first one to try and cheer someone up.

“She had this presence about her that just made you feel safe and respected,” Ren said. “She is going to be missed by many but forgotten by none.”

Ren added that Acker will be remembered as a “radiantly sweet person.”