Local media reports state that Ms Nance was discovered at around 9.15am on Thursday outside the Huntsville Public Safety Complex. A police officer found the body in an old and unused police vehicle as he was walking to a car in the parking lot.
AL.com reported that the Madison County Coroner’s Office found no evidence of foul play or trauma.
Police said that an autopsy and a toxicology analysis could provide further evidence on the cause of death this week.
Ms Nance’s sister Whitney Nance told WAFF that the family wants to see any available security footage.
“We do not believe that our sister would just randomly walk to a van and climb in it. First of all, why wasn’t the van locked on police property?” she said, adding that the family reported Ms Nance missing about two weeks ago and that they had been looking for her.
“She was in the van the entire time and nobody knew. Not even the police department knew,” the sister said. She added that when the family went to police headquarters asking to see surveillance footage, they were told that the investigator on the case was out of the office.
Whitney Nance said that her sister had been to the police department on numerous occasions to ask for help, and that family members had picked her up there several times after receiving calls from Christina Nance.
During a press conference on Sunday, relatives urged the police to release more information about the death.
News 19 reported that Frank Matthews, a cousin of Ms Nance, said during the briefing that “we really don’t know how our relative’s body was found inside a police van on police property and we need some justice”.
“We need some clarity and Christina cannot speak for herself,” he added.
WHNT reported that Ms Nance had been arrested several times for non-violent violations over the last eight years, most often for disorderly conduct.
A GoFundMe has been set up seeking help with funeral expenses.
Whitney Nance wrote on the page that “she was very loved, a very good person, a funny and fun person to be around!”
She added that her sister’s life “was taken too soon”.
“If you knew her you would love her spirit, she was very smart and loving,” she wrote. “I could go on and on about my beautiful sister.”
Leshia Young wrote on Facebook: “I went to school with Christina ... Her voice was sooooo soft, you had to mute the entire room just to hear her read aloud ... She was the quietest person I’ve ever known in my 29 years of living.”
She added that “she was [sweet], patient, and so subtle”.
The Independent has reached out to the Huntsville Police Department for comment.