The child whose body was found bound and wrapped in a tarp in Saginaw on Monday has been identified as 6-year-old Alanna Gallagher.
Saginaw police said Wednesday afternoon that Gallagher's death was being investigated as a homicide. The investigation is still in its beginning stages, police spokesman Officer Damon Ing said.
"As anybody can attest to, including parents, this is a disturbing case," he said.
Investigators with Saginaw police, the FBI and the North Texas Major Case Investigative Team will continue to work through the night to solve the case, Ing said.
"We're going to work through the night, as we have been, ever since we were notified of this crime, to make sure that we are relentless in our pursuit to ensure that the person responsible for this is brought to justice," he said.
"We send our heartfelt prayers to the family for the loss of their child," Ing said. "And as you can imagine, they are very distraught at this time."
Residents in Gallagher's neighborhood found the tarp in the middle of the street and, believing it to be garbage, looked underneath. Soon afterward, they called 911 to report the girl's body. They said she was found nude with her hands and feet bound and a bag over her head.
Her body was found at about 7:30 p.m. Her parents reported her missing at about 9 p.m., and neighbors say her father told them she was last seen at about 5 p.m.
Ing said that investigators do not know if Gallagher's body was intentionally left in the road or if it fell off a vehicle.
Saginaw police also do not know if Gallagher was abducted, he said. Her cause of death has not yet been determined, and investigators are still trying to establish a timeline of what led up to her death, he said.
Police believe the slaying is an isolated case, Ing said.
"I can assure the community of Saginaw and all surrounding areas that you're perfectly safe in this community," he said.
Saginaw police requested the FBI assist in their investigation. A FBI Evidence Response Team collected evidence and took photographs of the crime scene early Tuesday morning.
According to a FBI receipt of seized evidence, federal agents took a blue-gray tarp, electrical tape, and Wal-Mart plastic bags from a car registered to the victim's parents. The car is parked on the street in front of where the 6-year-old victim lived. Agents also searched the girl's home, where she lived with two siblings, her parents and another man.
The girl's uncle told NBC 5 that his niece's family had recently gone on a camping trip.
The family is not suspected in Gallagher's death, Ing said. Her family has been talking with counselors at the police department.
"We have many leads to follow -- not necessarily suspects individually -- but, at this time, the family is not suspected," Ing said. "We are basically trying to help them through their time of grief."
No arrests have been made in the case and no suspects have been named.
Gallagher's aunt, Teresa McDaniel said the child was very loved by her parents and siblings.
"I just broke down and cried," she said. "There was no speculation as to whether it was her, not her. When I read how she was found, I just broke down."
"I break down and cry when I hear one of these stories on the news, but to find out that's my niece -- that's something that you can't hold on to anymore," McDaniel said.
Gallagher was a "bubbly and always happy" kindergarten student at Willow Creek Elementary, the Eagle Mountain-Saginaw school district said in a statement Wednesday. The district's thoughts and prayers go our to her family and friends, the district said.
"We will continue to support our students, parents and staff that have been deeply affected by the events of recent days," Superintendent Jim F. Chadwell said. "It is imperative at this difficult time that we come together as a community to share our grief."
Police are looking for a red pickup truck with a splash of green paint that they believe may be connected to Gallagher's death but are also seeking any other information in the case.
Anyone with information is asked to call 682-888-3682 or 682-888-3684.
The FBI is offering a reward of up to $10,000 for information leading to the identification, arrest and conviction of the person or people responsible for Gallagher's death.
NBC 5's Ray Villeda and Scott Gordon contributed to this article.