The father of a 3-month-old girl who was found dead in a trash-strewn wooded area in the Bronx was turned in by his own dad — after allegedly confessing that he panicked when he discovered his daughter “stiff” and “cold” in her bed.

Damion Comager, 23, was taken into custody after his father told The Post he consulted with a priest and decided he had to “do the right thing” and call police about the death of his granddaughter, little Genevieve Rozzlyn Comager.

“I’m just trying to process this,” Donald Comager, 47, said Monday.

“He told me the baby was doing a lot of crying. She wouldn’t stop crying,” Comager said of his son. “He said he just shook her and lay her down, and he lay down and went to sleep.”

“He got up and reached for her and she was stiff and her body was cold. He panicked. He told his girlfriend, ‘I think she is dead.'”

The tragic girl’s body was discovered around 8:25 p.m. Sunday at West 161st Street and the Major Deegan Expressway, not far from the transitional housing shelter where she lived with her dad and 20-year-old mother.

The baby’s dad was charged with murder and concealment of a corpse Monday night at the NYPD’s 44th Precinct, cops said.

The baby’s mom, Ivana Paolozzi, was also arrested and charged with concealment of a corpse and obstructing governmental administration.

According to sources, David Comager allegedly admitted that he shook and slapped the baby on May 14 when she wouldn’t stop crying.

He allegedly said he didn’t want to take her to a hospital after she became unresponsive because she had marks around her neck that he feared would raise suspicion, the sources said.

Later that morning, the girl was stuffed in a bag and dumped in the wooded area near Yankee Stadium where she would be found more than two weeks later, according to the sources.

“They put the baby in a book bag and took her to the wooded area,” Damion Comager recalled his son telling him over the phone.

David Comager, who is originally from Louisiana, met the baby’s mother while traveling in Switzerland, her native country, and the couple moved to New York City in December — shortly before Genevieve was born in February, the sources said.

The elder Comager said Genevieve was his first grandchild, and although he never met her in person, he would call or FaceTime with his son and the baby every other day from his home in Louisiana.

Comager said his son told him about the baby’s death shortly before 7 a.m. Sunday.

“He just said the baby was gone,” he told The Post in a phone interview. “The baby was dead.”

He said he struggled with the decision to call the police after his son allegedly told him what happened.

“I called my pastor before I made the phone call,” Comager said. “We prayed and he told me he can’t tell me what to do but I should do the right thing. That’s when I made the call. That was my grandbaby.”

He said cops allowed his son to call him briefly late Monday afternoon.

“The cops let him talk to me,” he said. “He said, ‘I’m scared.'”

Damion Comager struggled with mental illness and was diagnosed bipolar and schizophrenic as a child, his dad said.

He had several prior arrests in the Pelican State on assault, domestic violence and criminal impersonation charges dating to 2021, according to NYPD sources.

Donald Comager said he took custody of his son when Damion was just 3 months old and raised him until he turned 17 and “he ventured out to see the world.”

“I’m hurting,” Comager said. “I want everyone to know my son loves his daughter.”