David "D.J." Creato Jr. told investigators that his 17-year-old girlfriend had threatened to leave him and that they argued about his 3-year-old son Brendan -- whom she disliked -- several days before the boy was found dead.

"We've always been breaking up over this -- three times now," Creato said in a questioning room at the Haddon Township Police Department less than 20 minutes after investigators told him they had found his son's body in woods near the Cooper River.

Prosecutors now point to Creato's remarks as motive. They say Creato killed Brendan to stop his girlfriend from leaving him in October 2015.

The girlfriend, Julia Stensky, now 19, was away at Pace University in New York City when Brendan died and has not been charged, authorities say. She and Creato met on the dating app Tinder in June 2015.

Jurors on Wednesday watched more than an hour of the video recording of Creato's interview with investigators. Jurors also heard the conversation that Brendan's mother, Samantha Denoto, secretly recorded when she spoke to Creato about a month after Brendan was found dead. Denoto did not live with Creato.

In the nearly hour-long conversation, which investigators had asked Denoto to record, Creato said he put Brendan to bed and woke up the next morning to find the boy missing.

Creato said that he thought authorities believed he was responsible for Brendan's death, which upset him, but that they were probably moving on to other suspects.

"I feel like I know the least out of anybody at this point," he said. "But I think they realize it's not me."

Creato told Denoto he was worried that Brendan had wandered off on his own and that "the wrong person" had found him. Creato also suggested another possibility: that spirits had drawn Brendan to the woods.

Creato, saying he did not mean to sound crazy, said there was perhaps "some kind of energy that guided him."

Michael Rhoads, the prosecutor's office detective who led the investigation into Brendan's death, testified for much of Wednesday, focusing on Creato's relationship with Stensky.

Rhoads read aloud transcripts of Tumblr posts written by Stensky, who called Brendan a "mistake" and said the boy would force Creato to stay in New Jersey forever.

"He is still a mistake -- your mistake," Stensky wrote in one post, about 10 weeks into their relationship. The post was intended for Creato, prosecutors said.

Stensky, they said, also wrote to Creato that "I think I legit love you, I can see myself having a future with you." But, she said, "you'll never get a kid from me -- ever. Not happening. One is more than enough in my opinion."

Rhoads said that he had planned to talk to Stensky about the posts, but that she canceled their meeting and hired a lawyer. Rhoads said he never spoke to her after that.

Creato had called 911 to report his son's disappearance around 6 a.m. Oct. 13, 2015.

The night before, according to Creato's interview with detectives, he had put Brendan to bed on the living room couch. Creato said that he then exchanged text messages with Stensky, and that she told him she was going to bed around 8:30 p.m. because she had a test the next day.

Creato, in the video, said he found it odd she was going to bed so early. He was also worried Stensky was talking to a man at school. So he called her  -- 10 times, according to authorities.

"I was just being jealous," Creato said in the video. "And I kept calling her."

Stensky never answered.

In the questioning room the next morning, investigators waited 51 minutes to tell Creato his missing son had been found — and lied when Creato asked.

Capt. Willie Mahan of the Camden County Prosecutor's Office asked Creato if he was withholding information. Creato said he was not.

When Creato was told his son had been found dead, he yelled, "Oh, God! No, no, no!"

Later in the interview, Creato told investigators it blew his mind that Brendan had been found near the Cooper River, three-quarters of a mile from Creato's apartment.

"I don't see him walking out the door and just leaving," Creato said, adding that Brendan had never done so before. Creato suggested the possibility that someone else had keys to the apartment.

But he also said of Brendan: "He's a very curious kid, he loves adventuring."

Creato had access to his father's black Chevrolet Silverado truck — which authorities later searched — and told detectives he had last used it the night before Brendan went missing.

Creato said he had driven to his family's house a few blocks away, but turned around to his apartment after learning his sister and mother — Brendan's aunt and grandmother — were walking the boy there. They had just given the boy a bath and put him in pajamas.

Wednesday was the third day of testimony.

Jurors are expected on Thursday afternoon to visit the area where Brendan's body was found. A narrow, downhill dirt path leads to the heavily wooded spot where Brendan's pajama-clad body was found slumped over a rock next to a creek. Prosecutors say Creato had visited that spot numerous times in the past.