Yes, due to the winter weather when Henry was killed, people had their windows closed and probably didn't hear anything.
Remember, though, there were two 10 year old kids going to a birthday party at 4 pm that afternoon on Suffolk. Their friend was Cliff Goodman. They found Henry's empty wallet and the perfume in the woods near the end of the road. It's in this article from 2004
16 Dec 2004, 74 - The Boston Globe at Newspapers.com
They left the items on a ledge in the woods behind Goodman's house where the birthday party was being held. The next day, the kids told their friend about what they had found. After school, about 2:30 pm, they met and went back to the woods to find the wallet and perfume. As they looked around, they spotted Henry's body. Poor kids, it really traumatized them.
There's no mention of the two boys seeing anyone that day. The kids must have wandered back into the woods a little ways to have found the items, because when they went to retrieve them the next day, they saw Henry's body nearby. IDK. But they just missed seeing the killer the day of the murder, because the birthday party started at 4 pm.