CENTRAL ISLIP, N.Y. (AP) — A suburban New York man drowned his mother in the family's backyard pool after she argued with him because he wasn't taking his medication, prosecutors said. 
 
 Denis Cullen was arraigned Thursday in Suffolk County on a charge of second-degree murder. 
 
 Newsday reports (http://nwsdy.li/2bF2m5U ) that the 23-year-old Cullen pleaded not guilty to killing his 63-year-old mother, Elizabeth Cullen. Bail was set at $5 million cash or $8 million bond. 
 
 Assistant District Attorney Robert Biancavilla said Cullen confessed to drowning his mother in the family's swimming pool on Long Island on Wednesday. 
 
 "This is a son who killed his mother, and the way he killed her, the way he describes, how it was done, is chilling," Biancavilla said. 
 
 Biancavilla said the two had argued over Cullen not taking his medication. The prosecutor said the argument escalated to the point where she poked him and Cullen put his mother in a headlock, walked her to the deep end of the pool and held her until she stopped struggling. 
 
 "He said she struggled violently and he was surprised a woman of her stature could struggle as much as she did," Biancavilla said. 
 
 After the arraignment, defense attorney Steve Fondulis described his client's demeanor as "calm." 
 
 "I have to determine if he had a psychiatric background. I have to determine if he's under a doctor's care," Fondulis told Newsday. 
 
 Elizabeth Cullen was the daughter of Maj. Gen. George William Casey, who was killed in a 1970 helicopter crash in Vietnam. Her brother, George William Casey Jr., is a retired general who last served as Chief of Staff of the U.S. Army. 
 
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 Information from: Newsday, http://www.newsday.com ||||| COLD SPRING HARBOR, N.Y. (CBSNewYork) — A prosecutor said a man charged with second-degree murder in connection with the death of his mother put her in a headlock, dragged her into a pool and drowned her. 
 
 Denis Cullen, 23, was arraigned on a murder charge Thursday for allegedly killing his mother, 63-year-old Elizabeth Cullen. Bail was set at $5 million cash or $8 million bond. 
 
 Elizabeth Cullen’s body was found outside her home on White Hill Road in Cold Spring Harbor on Wednesday, CBS2’s Carolyn Gusoff reported. 
 
 “Any murder that we deal with has certain aspects of it. This is a son who killed his mother and the way he killed her, the way he describes how it was done, was chilling,” Assistant District Attorney Robert Biancavilla said. 
 
 Biancavilla said they have a video confession in which Cullen admitted to fighting with his mother Wednesday morning after she scolded him for not taking his medication. 
 
 He said Cullen put her in a headlock, dragged her into the deep end of the pool and drowned her in a violent struggle. 
 
 “He said she struggled violently and he was very surprised that a woman of her stature could struggle as much as she did,” Biancavilla said. “He waited until she stopped moving and then carried the body out of the pool.” 
 
 He allegedly tried to hide his mother’s body next to a shed before stealing her wallet and car, Biancavilla said. He then went to the city where he confessed to his sister, prosecutors said. 
 
 Elizabeth Cullen’s body was found after Lloyd Harbor police were called to her home following a request to check on the welfare of the mother. 
 
 “Lloyd Harbor police received a call about a possible, intentional drowning,” Suffolk County Police Commissioner Tim Sini said. 
 
 When officers arrived, they discovered her body in the back yard and contacted Suffolk County police to help investigate, authorities said. 
 
 “While we were processing the scene, the suspect returned to the home and we placed him under arrest,” Sini said. 
 
 Cullen was arrested without incident, WCBS 880’s Marla Diamond reported. 
 
 Neighbors describe a childhood battling mental illness. Sources said Denis Cullen was once hospitalized after a suicide attempt. They are from a prominent military family. The victim was a daughter of famed Vietnam Maj. General George Casey and the sister of the U.S. Army commander of the same name. 
 
 Neighbors on the private road said she devoted her life to her children and are stunned by its tragic ending. 
 
 Cullen lived at the home with his mother. Authorities said he has no criminal history. 
 
 “There’s a lot of work to be done,” his defense attorney, Steve Fondulis, told WCBS 880’s Sophia Hall. “I have to determine if he has a psychiatric background, I have to determine if he’s under a doctor’s care and I have to look at the videotape.” 
 
 Cullen’s attorney says his client is not guilty. 
 
 If convicted, Cullen faces 25 years to life in state prison. ||||| A man charged with killing his mother by drowning her in their Long Island swimming pool Wednesday gave details of the crime in a taped confession, prosecutors said.Denis Cullen Jr., 23, of Lloyd Harbor, is facing charges of second-degree murder in the death of 63-year-old Elizabeth Cullen at their home on White Hill Road.During Cullen's arraignment Thursday, prosecutors said he told police during a multi-hour confession that he and his mother were in the pool when they got into a fight about him not taking his psychiatric medication.He had been diagnosed several years ago with paranoid schizophrenia and had been recently released from the hospital."He put her in a headlock, walked from the shallow end of the pool with her in the headlock to the deep end of the pool -- all the time while she was struggling," said Robert Biancavilla with the Suffolk County District Attorney's Office.Cullen drowned her there, according to prosecutors, and then took her body out of the pool and put it near a shed in their backyard, covering it with a dingy."He went into the house and took a shower. Went into his mom's wallet, took money out, credit card," Biancavilla explained. "Took her car to the Cold Spring Harbor train station. Took a train into Manhattan, he met up with his sister. He explained to his sister what happened. She notified her father. Then the three of them returned to the Lloyd Harbor residence where he was placed under arrest.""He said she struggled violently and he was very surprised that a woman of her stature could struggle as much as she did," Biancavilla said.Cullen's attorney said he spoke with with his client for about 20 minutes Thursday morning."He's pretty calm," said Steve Fondulis. "He hasn't been convicted of anything so he's not sorry at this point. He hasn't said 'I'm sorry.'"Cullen is being held on $8 million bail.Elizabeth Cullen ran Winn Collen Interiors out of Cold Spring Harbor. She was the daughter of the late Maj. Gen. George William Casey, who was killed in a helicopter crash in Vietnam in July 1970. Her brother, George Casey Jr., is a former Army chief of staff.
– In what authorities describe as a "chilling" case, New York police say a 23-year-old put his mother in a headlock and drowned her in the family's pool on Long Island on Wednesday. Assistant DA Robert Biancavilla says 63-year-old Elizabeth Cullen initially argued with her son, Denis Cullen, in the shallow end of the pool over whether Denis had taken his psychiatric medication. But when she poked him, per the AP, Denis dragged her into the deep end, "waited until she stopped moving, and then carried the body out of the pool," Biancavilla tells CBS New York. Biancavilla says Denis tried to hide the body before stealing his mom's car, cash, and credit card. He then traveled to his sister's house where he reportedly confessed. Police were called to the scene and found Elizabeth Cullen dead in the backyard. Biancavilla adds that Denis—previously diagnosed with paranoid schizophrenia, per WABC—later confessed. "He said she struggled violently and he was surprised a woman of her stature could struggle as much as she did," says Biancavilla, calling the description "chilling." Denis, who is the nephew of former US Army Chief of Staff George Casey, is charged with second-degree murder.