A Waterbury man has been arrested and charged in connection with his neighbor's untimely death.

According to the Waterbury Police Department, officers responded to a residence on Jewelry Street just after 8:00 PM on Saturday, August 3, after a report that an unconscious man, later identified as 61-year-old Keith Sullivan, had suffered a severe injury to the head and was bleeding profusely.

At first, it was reported to the officers that Sullivan may have fallen from his porch, hitting his head on the cement below. He was then transported to St. Mary's Hospital where he was treated for his injuries, but was pronounced on Monday, August 5 just before 4:00 AM.

As the investigation into Sullivan's death developed, police say that they determined the injury was not in fact caused by an accidental fall, but was caused by what they believe to have been an assault on the 61-year-old. As a result, city detectives located and arrested Sullivan's neighbor, 35-year-old Daniel Rosario (pictured above).

Rosario has been charged with assault in the first degree and was held on a $350,000 bond pending arraignment.

Both the manner and cause of Keith Sullivan's death is yet to be determined by the Connecticut State Medical Examiner.