"The police were there every week, all the time," said neighbor Gina Barbera.
On January 14th, Wang began to experience flu-like symptoms and checked himself into the hospital. Eleven days later, nurses uncovered the cause behind his symptoms, which turned out to be thallium poisoning.
A nurse at the hospital provided doctors with useful information that lead to the diagnosis when she remembered a similar case from China in the 1990's.
However, the diagnosis came too late as Wang entered a coma and died the next day.
"The odorless, colorless thallium is hard to detect and deadly. It is very uncommon and you would have to have access to it," said Dr. Arnold Pallay of Changebridge Medical Associates.
Li, 41, faced a judge in Middlesex County on Wednesday. In court, she appeared calm and quiet with a blank stare on her face.
The assistant prosecutor did not buy her demure appearance.
"It's our allegation that she administered a massive and lethal dose of thallium and caused his death," he said.
Neighbors remain worried about the couple's 2-year-old baby that may now grow up without parents.