It initially was believed that the remains found around 8 a.m. in Middletown were those of a baby who had been born alive.
But assistant county prosecutor Mike Cunningham said preliminary autopsy results showed that was not true, adding that the fetus was about 22 to 24 weeks old.
He said the case was no longer being investigated as a possible homicide.
Officials would not immediately provide further details, including how the remains ended up in the truck. They said the mother was juvenile who lived in Middletown, but would not disclose her name or any other personal information.
