State Police said several drivers reported four-foot lengths of reinforced steel bars called rebar, shovels, and concrete thrown from the bridge onto the interstate late Thursday night.
The last significant development in the case was in June when investigators searched an apartment on Union Street in Manchester where Harmony's father Adam Montgomery and stepmother Kayla used to live.
Photos and video show privacy tents set up in the front of the multi-family house on Union Street in Manchester, with a mobile police lab and vehicles in the street.
An unofficial count by Seacoast Current shows State Police responded to at least four fatal crashes involving drivers and pedestrians during the past week.