Prosecutors confirmed Saturday a man's body discovered by the Passaic County Sheriff's Department is the uncle of 3-year-old Janiay Rievas, who was killed last Saturday.

According to prosecutors, the discovery of 21-year-old Juan Mendez's body has changed the classification of the incident to a murder-suicide. Police searched the Passaic River and surrounding area since April 25 for Mendez, who they believe may have thrown his niece into the river after taking her from her home.

Police struggled to find Mendez after Janiay's body was discovered, prompting officers to suspect the man had killed his niece, but faked his own death. Prosecutors now believe the two deaths occurred simultaneously.

"I think it would be reasonable to conclude that he probably went into the water at the same time as the child did," Acting Passaic County Prosecutor Bruno Monjairdo says.

Police suspect Mendez was using drugs at the time of the incident. A toxicology test will be performed on his body to reveal any substances in his system.