The 911 call from a Texas mother that her 2-year-old daughter had gone missing in a park launched a massive search-and-rescue operation involving at least 163 people, including police and first-responders.

The mom, Tiaundra Christon, had recently returned to College Station after a trip to Houston to visit her boyfriend. Friends afterward reported believing they’d glimpsed the child with Christon, and surveillance video from a Walmart showed footage of the mother pushing what appeared to be her daughter in a stroller.

As investigators unraveled the woman’s claims, they learned Hazana had died days earlier and the mother and her boyfriend had dumped the body in a lake, according to the Galveston County District Attorney’s office.

A coroner could not determine the cause or time of the child’s death. But on Monday, Christon was sentenced to 20 years in prison after being convicted of tampering with a human corpse, PEOPLE confirms.

The boyfriend, Kenny Hewett, received the same sentence in November 2019, after pleading guilty to an identical charge, reportsKPRC.

Want to keep up with the latest crime coverage? Sign up forPEOPLE’s free True Crime newsletterfor breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.

A news release from the district attorney’s office describes the investigation.

A probable cause affidavit says that on Oct. 19, 2018, Hewett left the hotel with the child to get food, returning after 30 minutes with the toddler crying, reportsKHOU.

Hewett then began beating the child with a belt, according to the affidavit, and told Christon to do the same. But when he claimed she wasn’t hitting the child hard enough, Hewett resumed the beating himself.

While lifting her from the tub, Christon said she noticed the child had allegedly been sexually abused, the affidavit states.

With the little girl cold to the touch, Christon told police that she and Hewett used a hair dryer in an effort to warm her up, but the hair dryer burned her skin.

Hazana died that night, Christon said, according to the affidavit.

The mother hid the body inside a plastic bag in the backseat of her car for three days before, on Oct. 23, she and Hewett wrapped the bag with rope, and affixed a heavy rock to it.

A medical examiner testified at Christon’s trial testified that the injuries that caused Hazana’s bruising would not have been enough to cause her death, but she was otherwise unable to determine a cause that might have led to homicide charges.

Jurors deliberated for about 20 minutes before finding Christon guilty on Friday. They then spent 40 minutes deliberating on Monday before recommending the maximum punishment of 20 years in prison and a $10,000 fine.

Christon will be eligible for parole after serving at least five years.

source: people.com