In the hours before prosecutors said Ronald Steave killed two women and a 12-year-old boy, videos showed the three adults having sex together.

During Steave’s nonjury homicide trial Monday, the prosecution presented still images and video from late Dec. 30, 2021, into early New Year’s Eve that showed Nandi Fitzgerald and her friend, Tatiana Hill, having fun, drinking and singing together.

Steave joined the party just after midnight, said Pittsburgh police Sgt. Joseph Lippert, and was featured on camera with the women.

The last video was recorded at 2:38 a.m.

The victims were dead less than 90 minutes later.

In closing arguments, the defense used the video to try to convince the judge that Steave could not be the killer since the adults were all having fun together that night.

But the prosecution used it to show the cold-blooded nature of what they said occurred.

Deputy District Attorney Alison Bragle asked the judge hearing the case to find Steave guilty of three counts of first-degree murder.

Defense attorney Frank Walker argued that the prosecution failed to prove its case beyond a reasonable doubt.

Allegheny County Common Pleas Judge Edward J. Borkowski said he will deliver his verdict Tuesday morning.

Police said Steave killed Fitzgerald, 28, her son, Denzel “Buddy” Nowlin Jr., 12, and Hill, 28, around 4 a.m. at Fitzgerald’s home on Hamilton Avenue in Homewood.

Steave and Fitzgerald have a child together and had dated on and off.

The trial began Friday and concluded Monday afternoon. Originally it was set as a death-penalty case, but the prosecution withdrew notice of its intent to seek capital punishment last month.

On Friday, the prosecution called more than a dozen witnesses. Testimony continued on Monday with gunshot residue, blood and DNA evidence.

Both the prosecution and defense rested Monday afternoon. Steave chose not to testify.

Walker told the court that the prosecution failed to prove that his client killed the victims.

“They’ve proven Mr. Steave walked into that apartment,” the defense attorney said. “They proved three people are dead.”

But, he continued, it didn’t make sense that Steave would go from laughing and kissing the victims to killing them.

“All of a sudden he just goes on a massacre inside of the house?” Walker asked.

Instead, he proposed that Fitzgerald killed Hill and Denzel before killing herself.

Bragle dismantled that theory in her closing argument.

Fitzgerald was killed by a contact wound on the left side of her neck, but she was right-handed, Bragle said. Her blood was found on the stairwell leading up the steps. Hill and Denzel were found hiding in a third-floor bedroom of the house.

Bragle told the judge that what makes sense is that Steave killed Fitzgerald first — on the first floor of the house at the front door — and then went upstairs and killed Hill and the boy.

“He knows that he can’t leave because there are witnesses,” she said. “Why did they run, your honor? Because they heard the first shot.”

Denzel was found hiding behind a bedroom door, while Hill’s body was buried beneath clothes under a bunk bed.

“Why, your honor?” Bragle asked. “It’s because they ran.”

The prosecutor also highlighted the evidence linking Steave to the crime — gunshot residue found on his jacket and on the steering wheel of his car; video footage showing him leaving the house that morning and tracking his car and ammunition recovered in his car and house that matched markings on bullets used to kill the victims.

“Four people were in that house that night,” Bragle said. “Only one person walked out.”