(CNN) The family of a woman who was shot to death by Minneapolis police is making a desperate plea for information about the last moments of her life.

Justine Ruszczyk called 911 on Saturday night to report a possible sexual assault in an alley near her home, her fiancé, Don Damond, said in a news conference Monday.

Two police officers responded and one of them killed Ruszczyk. She died of a gunshot wound to the abdomen, an autopsy revealed.

Otherwise, police still haven't explained how, or why the shooting occurred , Damond said.

"Sadly, her family and I have been provided with almost no additional information from law enforcement regarding what happened after police arrived," a tearful Damond said as he struggled for composure.

"We've lost the dearest of people and we are desperate for information. Piecing together Justine's last moments before the homicide would be a small comfort as we grieve this tragedy."

Justine Ruszczyk, left, and fiancé Don Damond were set to marry next month.

One officer comes forward

Ruszczyk was originally from Australia, and her death has made headlines in both her native country and her adopted home in Minneapolis. Well-wishers contributed to a makeshift memorial in the alley near her home. Among stuffed animals and messages drawn in chalk a handwritten sign asked "Why did you shoot and kill our neighbor and friend?"

Vigil grows outside SW Minneapolis alleyway where neighbors say Justine Damond was shot and killed by an officer whose cameras weren't on. pic.twitter.com/jZBHg6lntG — Iris Pérez (@IrisPerezFOX9) July 17, 2017

The two officers who responded to the scene are on administrative leave, Minneapolis Police spokesman Scott Seroka said.

The officer involved in the shooting, Mohamed Noor, extended his condolences to the family in a statement through his attorney. Noor came to the United States at a young age and is thankful to have had so many opportunities, attorney Thomas Plunkett said.

Mohamed Noor has been identified as the officer who shot Justine Ruszczyk.

"He takes these events very seriously because, for him, being a police officer is a calling," the lawyer said. "He joined the police force to serve the community and to protect the people he serves. Officer Noor is a caring person with a family he loves and he empathizes with the loss others are experiencing.

"The current environment for police is difficult, but Officer Noor accepts this as part of his calling. We would like to say more, and will in the future," the statement said. "At this time, however, there are several investigations ongoing and Officer Noor wants to respect the privacy to the family and asks the same in return during this difficult period."

Piecing together what happened

The shooting occurred shortly before 11 p.m. on Saturday, Minneapolis Mayor Betsy Hodges said. The Minnesota Department of Public Safety is handling the investigation.

The officers were wearing body cameras, but they were not turned on during the incident, the mayor said. Per department policy , body cameras are supposed to be turned on prior to use of force "as soon as it is safe to do so" or during "any contact involving criminal activity."

"As mayor of our city, a wife, and a grandmother, I am heartsick and deeply disturbed by what occurred last night," Hodges said Sunday. "There are still many questions about what took place, and while the investigation is still in its early stages, I am asking the BCA to release as much information, as quickly as they are able to."

Minneapolis Police Chief Janeé Harteau echoed the mayor's concerns. She said the department has requested an expedited external, independent investigation to ensure transparency.

Statement from @ChiefHarteau Regarding Officer Involved Shooting pic.twitter.com/9FHNAckoHh — Minneapolis Police (@MinneapolisPD) July 17, 2017

In failing to turn on their body cameras, the American Civil Liberties Union of Minnesota accused the officers of thwarting "the public's right to know" what happened to Ruszczyk.

"These two officers should face penalties for breaking policy 4-223 and making the truth so much harder to find. Consequences should be added to the policy to ensure better compliance and accountability," Interim Executive Director Teresa Nelson said in a statement.

'Our hearts are broken'

Ruszczyk had resided in the United States since April 2014, a source who knew her said. She was living with her fiancé at the time of her death, and they were planning to marry in August.

"It is difficult to fathom how to go forward without her in my life," Damond said Monday. "Our hearts are broken and we are utterly devastated by the loss of Justine."

Don Damond, middle, mourns the loss of his fiancee, Justine Ruszczyk.

Ruszczyk has dual citizenship in the United States and Australia because her father holds US citizenship, the source said. The country's Department of Foreign Affairs and Trade said it is providing consular assistance to the woman's family.

"The death of Justine is a loss to everyone who knew her. She touched so many people with her loving and generous heart," Damond said Monday. "Our lives are forever changed as a result of knowing her. She was so kind, and so darn funny. She made us all laugh with her great wit and her humor."

'She was a healer'

According to her website, Ruszczyk trained as a veterinarian and later became a yoga instructor and life coach. She worked at the Lake Harriet Spiritual Community in Minneapolis.

Nancy Coune, an administrator with the Lake Harriet Spiritual Community, described Ruszczyk as a "gifted speaker" who imparted a message "of love and peace and non-violence."

"Justine was dedicated to helping others make transformations in their lives, through teaching and coaching. She was an amazing leader for bridging the gap between science and spirituality in a way that was easy to understand and fun. She had a great joy for spiritual growth that inspired those around her," Coune said in a statement.

"While this is a tragic event, Justine would want us to use this opportunity to develop greater love and compassion for each other, and look to find solutions by thinking differently."

"This woman was a beautiful light. She was a healer, she was loved. She should still be here," one woman said to applause.

"This should not have happened ... that could've been me, that could've been you, that could've been you, that could've been any of us," she added. "And we're gonna talk and we're gonna work as a community to make sure this doesn't happen again."