Police have released few other details of the incident, and it remains unclear why Willard was at the apartment complex or got tangled up with police.
Investigations by West Valley City and the Salt Lake County District Attorney's Office are ongoing. The two officers involved in the shooting remain on administrative leave.
The rally began at 3:30 p.m. in front of West Valley City's municipal offices, 3575 S. Market St. (3500 West). Nearly three dozen people, most of them strangers to Willard, attended the rally, some holding signs that read "Think First Shoot Later" and "Violence, Why?"
"I think it's just amazing that people would come out and support my sister and stand up for her and for what she can't say," said Willard's 19-year-old sister, Kayleen Willard, blinking back tears as she stood with supporters. "This doesn't make sense at all to me, and nothing that we know about it really adds up."
Willard had moved from Vancouver, Wash., to Utah in April for treatment at a drug-rehabilitation facility and had struggled with drug addiction, her family has said. After three months, she moved into an apartment in Murraywith Harrison, who had also been in treatment. Family had encouraged Danielle Willard to stay in Utah because she was doing so well, her mother, Melissa Kennedy, told The Tribune in November.
Harrison said Willard was working two jobs and had just bought an expensive camera so she could pursue her dream of becoming a photographer.
"She is an awesome friend. We told each other everything. She was always so happy and goofy," said Harrison, who learned of Willard's death through a television news report. "We held each other up a lot. She was doing really, really good ... and it's just ended, it's just gone."
On Sunday both Harrison and Willard's family members said they knew of no reason why she would have been at the West Valley City apartment complex where she died.
Kennedy visited the apartments for a second time on Saturday and said the concrete there is stained with her daughter's blood.
Kennedy has met with police but was only told her daughter was not armed and no weapon was found in her car. More recently, police called in an outside team of forensic specialists to look at the crime scene again and re-enact the events of Nov. 2, Kennedy said. She believes the effort suggests that police themselves have questions they are still trying to answer.
"And Danielle's not here to tell it," said Kennedy, adding that she doesn't expect any additional information from police for at least three weeks.
Willard's father, who is divorced from Kennedy, was also at Sunday's rally and said he was overcome with shock at the news of his eldest daughter's death. Fred Willard said he had tried contacting his daughter by text on the day of the shooting but never got a reply.
"I believe excessive force was used," Fred Willard said.
Willard's family said they find comfort in the outpouring of support they've received and appreciate that they are not alone in calling for justice for their daughter.
"Justice to me looks like questions answered and laws that get changed so that police officers are held accountable for what they do," Kennedy said.