Murder suspect and "cult mom" Lori Vallow Daybell pleaded not guilty on Tuesday in an Idaho courtroom to murder and conspiracy charges, among others, in connection with the deaths of several people, including Lori’s two children.

Daybell and her new husband, Chad Daybell, appeared in court on Tuesday after they were indicted late May 2021. Chad pleaded not guilty to all charges in June 2021.

Lori's next court proceeding will likely happen in October.

Lori Vallow Daybell's updated mug shot courtesy of Madison County Jail.

Lori Vallow Daybell returned to Idaho's Madison County Jail this week after spending months at a mental hospital. (Madison County Jail)

The pair is at the center of a tangled case that involves several suspicious deaths as well as a bizarre apocalyptic religious belief that prosecutors claim the couple designed to justify the murders of 7-year-old Joshua "J.J." Vallow, a 16-year-old Tylee Ryan and Chad's first wife, 49-year-old Tammy Daybell.

"I know justice will be served," Larry Woodcock, J.J. Vallow's grandfather, told media outside the courtoom.

Lori is also charged in Arizona with conspiring to kill her former estranged husband, Charles Vallow, with the help of her now-deceased brother, Alex Cox.

LORI VALLOW, CHAD DAYBELL 'DOOMSDAY' MURDERS: A TIMELINE OF EVENTS

The majority of Chad's hearing consisted of arguments, which included witness testimony, over where the trial should be held. The defense wants the trial to continue in Ada County, which houses Boise, due to media attention on the case.

The state argued that a sequestered jury from Ada County be transported to Freemont County to save costs,  FOX 13 Salt Lake City first reported.

Chad Daybell listens to a motion to move his trial during a court hearing in St. Anthony, Idaho, Tuesday, April 19, 2022.

Chad Daybell listens to a motion to move his trial during a court hearing in St. Anthony, Idaho, Tuesday, April 19, 2022.  (Tony Blakeslee/EastIdahoNews.com via AP, Pool)

Chad's attorney, John Prior, objected several times to the state's witness testimony and said prosecutors were "grandstanding." He also suggested it would be less expensive to not sequester the jury in Ada County. 

ALLEGED ‘CULT MOM’ LORI VALLOW MENTALLY COMPETENT TO STAND TRIAL, IDAHO JUDGE SAYS

In closing statements, prosecutor Rachel Smith said the case should continue in Freemont, where J.J. Vallow and Tylee Ryan "died," according to FOX 13.

"This is where the case should be," she said.

After spending about nine months in an Idaho mental hospital, Fremont District Judge Steven Boyce said in a Monday order that Lori is "returned to competency and is fit to proceed" in her murder trial, which was temporarily halted when she was committed to a mental health facility in June.

Joshua Vallow Tylee Ryan

Joshua Vallow, 7, and Tylee Ryan, 16. (Rexberg Police Department)

Vallow and Daybell were each indicted on multiple counts each of conspiracy to commit first-degree murder and grand theft by deception, first-degree murder and conspiracy to commit first-degree murder related to the deaths of J.J. and Tylee, officials announced at the time.

LORI VALLOW MURDER CASE PROCEEDINGS SUSPENDED AS COURT SAYS SHE 'LACKS FITNESS TO PROCEED'

The children were missing for several months — when police say the couple lied about the children’s whereabouts and then slipped away to Hawaii — before their bodies were found buried on Chad Daybell’s property in rural Idaho.

Investigators say Chad and Lori Daybell began espousing an unusual, doomsday-focused system of religious belief involving "zombies," teleportation and communication with other spiritual realms starting in 2018, when both were still married to other people. The Idaho prosecutors say they used their religious beliefs to justify or encourage the murders.

Chad Daybell listens to a motion to move his trial during a court hearing in St. Anthony, Idaho, Tuesday, April 19, 2022.

Chad Daybell listens to a motion to move his trial during a court hearing in St. Anthony, Idaho, Tuesday, April 19, 2022.  (Tony Blakeslee/EastIdahoNews.com via AP, Pool)

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Lori reportedly believed she was "a god assigned to carry out the work of the 144,000 at Christ’s second coming in July 2020," according to divorce documents Charles Vallow filed before his death. Chad Daybell has written several apocalyptic novels based loosely on Mormon theology. Both were involved in a group that promotes preparedness for the biblical end-times.

Daybell's arraignment proceeding will take place on April 19.

Fox News' Stephanie Pagones and The Associated Press contributed to this report.