Jurors in the trial of David "D.J." Creato Jr. told a judge Tuesday they were unable to reach a verdict, following three days of deliberation.
Judge John T. Kelley ordered the jurors to return Wednesday to Superior Court in Camden to deliberate again, telling them to "make an effort" to reach a verdict.
Creato, 23, is charged with killing his 3-year-old son, Brendan, and dumping the boy's body in Haddon Township woods in 2015.
The jury has spent hours reexamining evidence, and on Tuesday watched video of Creato reacting to news of Brendan's death for a fourth time.
The jury also asked to hear about a photo of woods discovered on Creato's phone. The photo was taken on Oct. 11, 2015, within 15 yards of where Brendan Creato was found dead two days later, according to an audio recording of testimony that was replayed in court.
The video of Creato's interview with detectives was played on a projection screen. It showed him screaming "Oh my God, no, no, no," when he was told his son had been found dead.
The jurors also twice reexamined the activity on Creato's phone from the night Brendan disappeared.
A PowerPoint presentation of the activity showed Creato repeatedly called his girlfriend, Julia Stensky, then 17, and logged into her Facebook and Snapchat accounts that night.
Prosecutors have said Creato killed Brendan to stop Stensky, who demanded she be Creato's number-one priority, from leaving him.
Stensky, now 19, was in New York City when Brendan died, authorities said. She has not been charged.
Creato called 911 just after 6 a.m. on Oct. 13, 2015, saying he woke up and Brendan was gone. Minutes prior to that, Creato had called his mother, Lisa, and Brendan's mother, Samantha Denoto, who did not live with Creato.
Around 6:40 a.m., as the search for Brendan was underway, Creato checked Stensky's Snapchat account.
Two police officers, following a police dog that tracked Brendan's scent, found his pajama-clad body in woods three-quarters of a mile from Creato's apartment just before 9 a.m.