Suffolk police homicide detectives investigate on White Hill Road in Lloyd Harbor Wednesday night after 63-year-old Elizabeth Cullen was found dead in the backyard of her home. Her son, Dennis D. Cullen Jr., was later arrested and charged in connection with her death. (Long Islander News photo/Jano Tantongco)

A Lloyd Harbor man had been charged in connection with the drowning death of his mother, Suffolk police said.

Lloyd Harbor police officers found 63-year-old Elizabeth Cullen dead in the backyard of her White Hill Road home in Lloyd Harbor at around 3:45 p.m. yesterday. Lloyd Harbor police were responding to a request to check on the woman's "welfare," according to police.

Suffolk Police Homicide Squad detectives were contacted and began an investigation.

"The evidence suggested that she was intentionally drowned," Timothy Sini, Suffolk County Police Commissioner, said during a news conference last night.

While police processed the scene, 23-year-old Denis D. Cullen Jr. returned to the home, Sini said. He was arrested and charged with second-degree murder at around 5:50 p.m.

Cullen was arraigned at First District Court in Central Islip this morning. He pleaded not guilty. Bail was set at $5 million cash and $8 million bond.

Cullen admitted to Suffolk homicide detectives that he killed his mother following an argument that started after he did not take his medication, according to Robert Clifford, a spokesman for Suffolk District Attorney Thomas Spota.

Cullen is being represented by Port Jefferson-based attorney Steve Fondulis.

This story is developing.

-ANDREW WROBLEWSKI

Editor's note: This story was updated at 1:30 p.m., Aug. 18.