Yang is charged in the death of Ronnie Reuter, the pregnant girlfriend of former Chicago Bears player Shaun Gayle.
The jury received instructions Monday afternoon from the judge while both sides prepared for closing arguments.
While the defense rested without allowing Yang to testify in her own defense, prosecutors offered testimony from the victim's brother as well as from a doctor who says that a defense wound on Reuter's body shows that she was trying to defend and protect her child from the attack.
Thad Reuter and his family left the Lake County Courthouse Monday afternoon without comment after testifying at his sister's murder trial.
The younger brother of murder victim Rhoni Reuter took the stand during the seventh day of testimony in the trial of Marni Yang. Yang has been charged with murdering a pregnant Reuter and homicide of a fetus for killing Reuter's unborn child.
"We're extremely satisfied with all the evidence that we've been able to put in at this time," said Patricia Fix, assistant Lake County state's attorney.
The prosecution maintains Yang targeted Reuter on October 4, 2007, because she considered the part-time department store worker a rival for the romantic attention of ex-Chicago Bear Shaun Gayle, who had relationships with both women.
Reuter was pregnant with Gayle's child.
"This has been absolutely devastating to him," said Donna Rotunno, Gayle's attorney. "Regardless of what anybody says about him, we can't change the outcome of what happened here in this case. His life is forever different and has been forever changed."
Court began with the testimony of Dr. Manny Montez, who told the jury of nine men and three women that Reuter was shot six times, two of which struck her daughter in the head and abdomen. The forensic pathologist testified, saying, "The bullet pulverizes the right kidney, aorta and cuts the spine in half."
Montez added, that while either bullet would have killed the baby, Reuter was killed by a gunshot wound to the head.
Yang sat emotionless as the jury looked at the gruesome autopsy photos. A 43-year-old Yang did not testify in her own defense, but her mother did along, with a neighbor of the victim and an investigator, all in an effort to discredit Friday's testimony of Yang's friend Christie Paschen. The self-proclaimed psychic who wore a wire for authorities says that Yang told her about committing the murder and helped her dispose of evidence.
Closing arguments are set to begin Tuesday. After that finishes up the jury will decide the fate of Marni Yang.