UPDATE SEPT. 4: The mug shot of Joshua Oxford has been released.
UPDATE AT 5:35 P.M. The father of the three-year-old boy found dead Monday morning says his son was a loving and compassionate toddler who was inseparable from his younger brother.
James Theriot told 13 Action News that he is working to get to Las Vegas from his home in Texas after getting the call about his son's death early Monday morning.
Theriot said he is hoping to get his two-year-old son from family services after their mother and her boyfriend were arrested in connection with the death of three-year-old Daniel Theriot.
James Theriot said a friend has set up a GoFundMe account in an effort to raise money for expenses.
UPDATE AT 1:55 P.M. Police have released mug shot of the mother of missing boy who was found dead. Her name is Cassie Smith.
The boyfriend has been identified as Joshua Oxford. They are both facing one count of child abuse or neglect. Murder charges are currently pending the cause and matter of death which will be provided after an autopsy.
PHOTOS: Mug Shots Making Headlines
UPDATE AT 6:50 A.M. According to Las Vegas Metropolitan Police Department's Lt. Ray Spencer, the search for the missing 3-year-old boy has turned into a homicide investigation.
Spencer said a 911 call was received from a 20-year-old woman on Sunday morning who reported she went to park with the child, who was identified as Daniel Theriot. She claimed that her child walked away while she was on the phone.
At about 1 p.m. Sunday, police began doubting the mother's story, including wondering if the child was ever at the park. A criminal investigation was launched at that time in addition to the missing person investigation. One of the reasons they doubted the story was because the woman lived within walking distance of Lorenzi Park but chose to go to a park several miles away.
The child's body was located in a remote area near Lake Mead early Monday morning. Police have arrested the mother and her boyfriend, a 40-year-old male.
Interactive Map: Murders investigated in the Las Vegas valley in 2018
Police say that the manner in which the child was killed was "absolutely disturbing" and there is "nothing accidental" about the death of the child.
Police believe the child was killed within 12 hours of the initial report of the child's disappearance.
Lt. Spencer also said that a 2-year-old child was removed from the couple's home and they will also be charged with abuse of that child.
The case is similar to that of a 3-year-old girl reported as missing on Aug. 23. The child's mother, Aisha Thomas, claimed that her daughter disappeared on a walk to a nearby grocery store. The child's body was found in a duffel bag in a closet in the child's home.
Lt. Spencer reference the death of that little girl during this morning's press briefing.
UPDATE AT 5:20 A.M. SEPT. 3: Police are no longer actively searching for the 3-year-old boy who was reported missing at Sunset Park on Sunday. No reason has been given at this time. There will be a media briefing at 6:45 a.m. today.
UPDATE AT 6:30 P.M. Las Vegas police tell us that they are bringing in equipment to search the pond at Sunset Park.
UPDATE AT 2 P.M. Las Vegas Metropolitan Police officials have released more details about the 3-year-old boy who went missing from Sunset Park Sunday morning.
Daniel Theriot may be suffering from emotional distress and require medical attention.
He is a Caucasian male last seen wearing a red t-shirt with a Lightning McQueen logo along with red and black plaid pants.
Anyone seeing the child is asked to call 702-818-3111.
Sunset Park remains closed as the search for the child continues.
Sunset Park is comprised of 300 acres with a 9-acre lake, 3.5 miles of trails, playgrounds, a dog park, softball/baseball fields, tennis courts and more. It is located near McCarran International Airport on Sunset Road.
Officials have closed Sunset Park as Park Police and Las Vegas Metropolitan Police search for a missing child.
The 3-year-old boy was reported missing at around 9:19 a.m. Sunday.
Officials have not provided any other details at this time.
We have a news crew en route and will update this story as we get more details.