Taylor Cournoyer, 21, and Laurie Cournoyer, 29, are charged with failing to notify police of the death and five counts of child abuse related to other children who live in the home with them.
The couple is accused of using sleeping pills, methamphetamine and marijuana during the day and a half in July when the child's death still hadn't been reported.
They are the first people charged under a South Dakota law passed earlier this year that says a parent, guardian or caretaker who knowingly fails to report a child's death within six hours could face a felony charge punishable by up to five years in prison. It was modeled after Florida's "Caylee's Law," which was passed following the high-profile death of 2-year-old Caylee Anthony, who wasn't reported missing until 31 days after she vanished in 2008 in Orlando.
The South Dakota couple, who were caring for the toddler but are not her parents, pleaded not guilty Tuesday to the charges at a hearing in Charles Mix County Court in Lake Andes, about 120 miles southwest of Sioux Falls.
An 11-year-old boy also has been charged, but details of his alleged involvement are not being released because he is a juvenile.
According to police affidavits, Laurie Cournoyer had a difficult time recalling recent events and the last time she had seen the toddler. At one point when questioned about the exact time, she said, "Maybe it was yesterday, I don't know." She could not recall who had placed the toddler in the closet.
When an investigator asked Taylor if the kids came in for supper on July 3, he said no. The family had "kind of roughed it this month" and "really didn't cook dinner" because most of their food was gone, he said, according to the affidavit.
An autopsy was done, but the girl's cause of death hasn't been released.
Charles Mix County prosecutor Pam Hein referred questions to the South Dakota Division of Criminal Investigation. A representative from the agency did not immediately return a message seeking comment.
A lawyer for Taylor Cournoyer could not be reached, while Laurie Cournoyer's lawyer, Scott Swier, said he could not comment other than to say he will "vigorously defend" his client against the charges.
Following news of the girl's death, the Wagner police chief who helped investigate the death resigned from his post after he was charged in an unrelated case with failing to report a crime. In that case, prosecutors allege Jim Chaney, 44, tried to cover up his girlfriend's methamphetamine use by hiding her used needles in his office.
Both the girl's death and Chaney's arrest show the perils methamphetamine is playing in the community, said Frances Zephier, a Wagner resident who has organized protests for what she says are lax enforcement of drug laws in the area.
"She gave her life and was tortured so our people could be free of methamphetamine and we're not going to stop. It's all to honor her," Zephier said of the toddler as her voice wavered.
Zephier, a member of the Yankton Sioux Tribe, said drug use has been plaguing the tribe for the past 20 years. Charles Mix County encompasses all of the Yankton Indian Reservation, which is home to the Yankton Sioux Tribe.