The military-grade explosives found at a historic New York City cemetery are more than 13 years old, police said Tuesday.
It was still unclear who placed the plastic bag of C-4 at the foot of a tombstone in New York City Marble Cemetery on Manhattan's Lower East Side.
A caretaker planting shrubs in the cemetery dug up the bag in May or June 2009, didn't realize what it was and left it.
It remained in the back, near a tree, until a volunteer saw it over the weekend and put it in a trash can, thinking it was some a leftover movie prop because the cemetery is often used as a film setting, police said. But the volunteer thought it might be dangerous and called police Monday.
The discovery caused a bomb scare and shut down the area until police determined it couldn't detonate.
NYPD spokesman Paul Browne said Tuesday that the eight M-112 sticks were tested and did not have an identifying piece that all military C-4 were required to have after 1997. The identifier is used so military members can figure out where it has exploded, if necessary.
The grave at which the bag was found was dated 1919 and belonged to Henry Borraem and family, police said. The cemetery, which was designated a landmark in the 1960s, is usually closed to the public.