A prosecutor described in graphic detail Thursday the last hours of Holly Bobo's life, telling jurors about how she was beaten and "gang-raped" before being shot in the head at point-blank range by the man on trial for her murder.

"They ripped Holly's clothes off -- her blue jeans and her panties -- and one by one they lined up," prosecutor Jennifer Nichols told jurors in closing arguments. "They took turns."

"That's what she went through her last morning on earth. Then she was murdered -- plain and simple," Nichols said, before holding up an image of Holly's skull in one hand and a photo of the beaming, blonde-haired nursing student in the other.

Nichols' words concluded the prosecution's closing argument in their case against Zachary Adams, who is on trial for kidnapping, raping and murdering the woman. Bobo was 20 years old when she was taken by a stranger outside her family's rural home in Darden, Tenn., on April 13, 2011. Her partial remains turned up in woods near Adams’ home — about 10 miles to the north — in September 2014.

Jurors started deliberating Thursday afternoon. If convicted of murder, Adams could face the death penalty.

Prosecutors said three other men took part in the crime: Jason Autry, a co-defendant who testified in detail about his role in the murder, John "Dylan" Adams, the defendant's brother, and Shane Austin, who committed suicide in 2015.

Zachary Adams, 33, has pleaded not guilty to felony first-degree murder, especially aggravated kidnapping and aggravated rape. In closing arguments, defense attorney Jennifer Thompson told jurors that Adams is "one hundred percent innocent of the charges he faces in this case."

Thompson, who spoke for nearly two hours, said the prosecution's theory was "full of holes" and claimed there was no evidence directly linking Adams to the murder.

"The cases in criminal court are not about what is possible, but what is provable without a reasonable doubt," Thompson said in her closing statement.

Autry had testified that Adams asked for his help in disposing Bobo's body. The two men drove to the Tennessee River with Bobo wrapped in a blanket in the back of a pickup truck, according to Autry. The plan, he told jurors, was to “gut her” and “put her in the deep end” of river so that her body would not float to the water’s surface. But when Bobo — who was thought to be dead — moved her foot and made a noise, Adams shot her in the head as Autry made sure no one else was watching, he testified.

Thompson called Autry's version of events "ridiculous" and claimed he concocted a lie so the state would not seek the death penalty in his case.

"Jason Autry has sold his death penalty to the government," Thompson said. "The only price he had to pay was this tall tale he came up with in January."

Thompson said the man responsible for Bobo's murder is Terry Britt, a convicted sex offender known locally as "Chester the Molester" who was at one time considered a suspect by the Tennessee Bureau of Investigation.

Earlier Thursday, Assistant District Attorney Paul Hagerman said Adams described the murder weapon to a fellow inmate before it was known to investigators and had "cracks in the secret" from the beginning.

The inmate, Shawn Cooper, testified that Adams asked him in March 2014 to tell his brother to "keep his mouth shut" or he would "put him in a hole beside her."

At the time, both he and Cooper were being held at the Chester County Jail in separate cases. Cooper was awaiting transfer to Obion County Jail, where Adams' brother was being held.

"He said, 'I'm not worried because they got no body and they got no gun,'" Hagerman quoted Adams as saying at the time.

The alleged murder weapon -- a .32 caliber gun -- was not found by investigators until early 2017, Hagerman noted to jurors. Bobo's remains were found in September 2014, six months after the alleged conversation between Adams and Cooper.

"Who knew in March 2014 that she had been shot?" Hagerman said. "Her body hadn't been found."

"Nobody in this world knew if she was strangled ... stabbed," Hagerman said.

"Nobody in this world knew except the two men who were there when it happened," he said, referring to Adams and Autry.

As the state wrapped up its case, jurors were shown the "promise ring" that Bobo's boyfriend gave her for Christmas in 2010. The prosecution also showed them her notebook -- with “Student Nurse” and a smiley face written on the cover -- and the bagged lunch Bobo's mother had packed for her that morning.

Bobo was "just trying to be the best student nurse she could possibly be," said Nichols.