Chattanooga Police revealed Monday that acid was poured over the body of 10-year-old Joshua L. Walden, who died of "mechanical asphyxia/suffocation" in East Lake a year ago.
Det. Mike Mathis said at a press conference that the information had been withheld, but it was now being brought forth in hopes it will help bring a break in the mysterious case.
Det. Mathis said investigators who first examined the body noticed there was something "very unusual." He said it appeared something had been poured on the body to make it appear it had been burned. He said the acid was poured after the boy had been killed.
He said acid was on the body, under the body, and on leaves nearby.
Det. Mathis said tests showed the material was a corrosive acid, similar to a type used in cleaning concrete or metal - as at a car body shop.
He said a check was made with the FBI to see if there were similar cases across the country, and none were found involving a child. He said five FBI experts came here last January to help go over evidence.
A report from the FBI's National Center for the Analysis of Violent Crimes was that it is believed the killer "came from the immediate neighborhood."
It says, "The significant feature is the choice of the immediate neighborhood as the body disposal site. Research has shown that when operating under severe stress, individuals tend to revert to the familiar. In other words, the offender was comfortable in the neighborhood, thus that the offender lives or has spent considerable time in the neighborhood."
The report says the "killer used acid because he is familiar with it or has ready access to it. The offender does not kill the victim and then purchase acid. He uses what is readily available to him and what he is comfortable handling."
The report says the murderer "was probably involved in an occupation or some activity in which acid was utilized."
Det. Mathis also said that Joshua's socks and tennis shoes have been never found.
He said the family was only recently told about the acid. He said they were "shocked and very disturbed."
He said the family has been "extremely helpful" in working the case.
The red bike that he was last seen riding on a Friday afternoon is also still missing. The body was found the following Sunday morning.
Chief Jimmie Dotson said detectives have spent hundreds of hours on the case and are still actively working it.
An earlier report from the Hamilton County Medical Examiner listed the case as a homicide and stated, "decedent's respiration mechically restricted."
It said there were superficial abrasions on the nose and right side of the face.
Joshua was a student at East Lake Elementary School.
Joshua, when last seen, was wearing a red shirt and black jeans and was riding a red 20-inch bicycle.
Officials said Joshua was known to ride his bike near East Lake Park.
He was 4'5" and weighed 60 pounds. He had blue eyes and light brown hair.