The New York City Medical Examiner's Office is joining NYPD investigators at the site where Etan Patz is thought to have been killed more than 30 years ago.
It's not clear what they are looking for, but the ME says they will assist officers should they find any clues.
Police returned to the SoHo shop on Wednesday where Patz, 6, allegedly disappeared in 1979.
Now an eye glass store, the shop was once a bodega where Pedro Hernandez worked.
He confessed to killing Patz in 1979 and dumping the boy's body in the trash.
Hernandez's attorney says his client is bipolar and schizophrenic.
He faces second degree murder charges and is due back in court in October.