Hudson’s sister, Julia Hudson, also left the courtroom before the photographs were displayed on a large screen, though the star’s fiance, pro-wrestler David Otunga, stayed.

Earlier in the day, Hudson hung her head and closed her eyes as Chicago police Sgt. David Dowling described finding her mother’s body in the living room. Dowling described finding Jason Hudson dead in his bed, with the sheets pulled up as if he had been sleeping.

Jennifer Hudson, wearing a black top, green skirt and knee-high leather boats, sat in a fourth row bench well within view of jurors for much of the day Tuesday. Most of the time she seemed composed and engaged, leaning forward to get a better look at a witness.

Another officer testified about the frantic search for Hudson’s nephew, Julian King, who was found in an SUV three days later. Prosecutors also played a surveillance video showing Balfour getting out of a car at a gas station near the Hudson house on Chicago’s South Side before the killings. Prosecutors are trying to show he was in the area at the time — something Balfour has denied.

An auto mechanic who saw Balfour a few hours before the Oct. 24, 2008, triple homicide seemed to surprise prosecutors when he testified he never told a grand jury that Balfour told him he had a gun. Even after his grand jury testimony was read to him from a transcript, he persisted.

“He (Balfour) never said nothing about a gun. He just said he was dirty,’’ Tyrone Dunbar said.

With no surviving witnesses to the murders, prosecutors must offer overwhelming circumstantial evidence that Balfour committed the crime. One challenge will be tying Balfour to the alleged murder weapon, a silver and black .45-calibre handgun.

Prosecutors claim Balfour targeted the family in a horrific act of vindictiveness against his ex-wife. They believe he became enraged by balloons he saw at the home that he thought were from her new boyfriend.