The search for Jade Morris ended Friday afternoon when officials confirmed that it was her body that was found a day earlier in an undeveloped housing tract.
The Clark County coroner's office said she died of multiple stab wounds.
Jade was last seen Dec. 21 with family friend Brenda Stokes Wilson, who picked her up to go Christmas shopping.
Wilson, 50, returned the car she had borrowed for the outing to a friend two hours later. Jade never came back. Investigators later found blood on the driver's door and steering wheel of the 2007 Saab sedan.
Later that night, Wilson was wrestled to the ground with razors in each hand after allegedly slashing the face of a female co-worker at the Bellagio casino.
A judge raised her bail to $60,000 from $600,000 Friday morning after she was identified as the prime suspect in the child's killing.
"It's no secret the defendant is the suspect in the murder of 10-year-old Jade Morris," prosecutor Robert Daskas told Senior Clark County District Court Judge Joseph Bonaventure at the hearing.
Later Friday, Las Vegas police homicide Capt. Chris Jones said investigators were still moving forward.
"As soon as we get all the evidence in that we need, we'll book her on the murder charges," he said.
Wilson has been jailed since the 21st on felony battery with a weapon, burglary and mayhem charges that could get her decades in prison.
Police said she offered no help in the search for the missing girl. Murder and kidnapping charges could get her life in prison without parole or the death penalty.
On Thursday, Las Vegas police responding to a 911 call found a girl's body in unkempt brush near palm trees in a small traffic circle about 10 miles from the downtown Las Vegas outlet mall where Stokes was to have taken the girl shopping.
On Friday evening, Jones called the slaying "unfathomable."
"Even having our jobs, we still can't wrap our heads around this," he said. "A lot of people think that just because of our positions we can understand it, but we can't."
In court Friday morning, Wilson stood flanked by eight police officers as her lawyer, Tony Liker, clutching a Bible and a copy of the charging documents, asked the judge to postpone arraignment until Wednesday to give him time to meet with Wilson.
Wilson, who had been identified by police and prosecutors as Brenda Stokes, told the judge Friday that her full name was Brenda Stokes Wilson.
Jade's father, Philip Morris, was removed from court Wednesday by armed court officers after shouting questions about his daughter's whereabouts to Wilson. He did not attend Friday's hearing.
The two dated for several years, and Jade had a long and trusting relationship with Wilson, according to the girl's grandfather, Philip Tucker.
Tucker said Philip Morris lived in Billings, Mont., and worked at a Flying J truck stop for more than a year. He would stay with Wilson when he visited Las Vegas, Tucker said.
Authorities have not disclosed a motive for the slaying. But Tucker said Wilson appeared to believe that the face-slashing victim had become romantically involved with Philip Morris.
Wilson picked up Jade for their shopping expedition around 5 p.m. Later, she got a ride with a friend to the Bellagio. She allegedly attacked her co-worker, Joyce Rhone, at around 9:30 p.m.
Rhone, 44, was hospitalized with deep cuts on her face, including one from her ear to the edge of her mouth.
Wilson told investigators that she visited her doctor last week, seeking to be admitted to a hospital "due to feeling like she wanted to hurt someone."