CONEY ISLAND, Brooklyn (PIX11) – The Brooklyn mom accused of drowning her three kids admitted that “she had hurt her children” and that “they are gone,” a criminal complaint alleges.

Erin Merdy, 30, was arraigned on murder charges Friday. She allegedly drowned her three children – Zachary Merdy, 7; Lilana Merdy, 4 and 3-month-old Oliver Bondarev – at a beach in Coney Island early Monday.

Merdy was arraigned remotely from the hospital where she was sent for a psychiatric examination, the Associated Press reported.

Merdy was allegedly caught on video walking on the beach toward the water with her three children around 12:54 a.m. Monday, according to the criminal complaint.

Police took Merdy into custody after they found her barefoot and wet on the boardwalk, police officials said. That was about 90 minutes after a relative called 911, worried that Merdy intended to harm her children, authorities said.

A relative told police that Merdy had suffered from postpartum depression, something she may still be going through, sources told PIX11 News.

The father of 7-year-old Zachary had been fighting for full custody of his son before the boy’s death, according to a family friend.

“He was my only child, my heartbeat, and the most devoted and loving person I have ever had the pleasure of being around,” Derrick Merdy, Zachary’s father, wrote in a GoFundMe. “He was such a magnificent person sent by God. He had a smile that could light up any room and truly liked people. Zachary was incredibly imaginative, compassionate, and sincere.”