Niagara Falls, N.Y - It was a grisly discovery.

In a trash bag, buried in a garbage can in the 500 block alley of Third St., Niagara Falls, N.Y., police officers found the body of a little girl who been reported missing just hours earlier on Monday morning.

By mid-afternoon Monday, detectives said they were ready to charge one 16-year-old boy with Isabella Sarah Tennant’s slaying and another teen with helping dispose of the body.

“It’s a terrible crime. It tears at your heart,” said Capt. William Thomson, the veteran commander of the Criminal Investigation Division. “I have grandchildren that are the age of the victim.”

Early Monday evening, police confirmed that they had charged a 16-year-old boy with second-degree murder and an 18-year-old with tampering with evidence. The pair will be arraigned on the charges in Niagara Falls City Court Tuesday morning.

The tragedy began unfolding about 6:20 a.m., when patrol officers were called to a home for a report of a missing five-year-old. The great-grandmother of Isabella told police the child had disappeared overnight.

“The great-grandmother said she went to bed at 10:30 p.m. and left the five-year-old with (one of the accused),” Thomson said.

Members of Isabella’s family told investigators that the younger of the two accused was a “close” and “trusted” family friend and that it was not uncommon for him to be in the great-grandmother’s home and around the little girl without supervision.

While detectives located the 16-year-old and questioned him, Falls police patrol officers began an intensive search for Tennant.

In addition to flooding the area with officers, police also brought in a search dog from the Niagara County Sheriff’s Office. Three hours after the search began, investigators got a huge break in the case.

“At 10 a.m., a party showed up at (police headquarters) and said he had information about the missing girl,” Thomson said.

The person Thomson was referring to was the 18-year-old and he then led police to the trash can in an alley.

“(Isabella’s body) was in a trash can, under some other bags of trash,” Thomson said. “Her body was inside a trash bag.”

While the younger accused boy had reportedly denied harming the child, detectives said the older confessed that he had helped his friend dispose of Isabella’s body.

Investigators said they believe Isabella was killed in her great-grandmother’s home and that her body was then taken to the trash can. Thomson said there were some signs of trauma on Tennant’s body, but no evidence of sexual abuse.

In a statement released Monday night, detectives said, “At this time we believe (the younger accused) killed Isabella with his bare hands and that (the older) was only involved after she was deceased.”

An autopsy to determine the exact cause of Tennant’s death is set for Tuesday morning.

- Niagara Gazette