HALLSVILLE - Jodi McGrew's family knows how she died. Now they want to know why her brother-in-law may have wanted to brutally murder her Tuesday in a bedroom of his parents' LeRoy home. | VIDEO: Mom reflects on daughter's death | Updated photo gallery | Suspect wrote emotionally dark poems | Jodi McGrew's obituary

Jason Marksteiner remained in jail Friday on charges that he murdered the pregnant woman. The 21-year-old LeRoy man also is accused of sexually assaulting McGrew and intentionally killing her unborn child.

Sandra Zogg received a call at work Tuesday morning from her husband, Mike Zogg. The coroner's office had come to their Hallsville home with news of their daughter's death. Then a call came from McGrew's sister, Samantha, who is married to Marksteiner.

"Samantha called and said that Jason killed her," Sandra Zogg recalled through repeated sobs.

Police say Marksteiner admitted to the rape and murder, but McGrew's family wants to know why.

"I just want to know why because 'I wanted to' is not the right answer," Sandra Zogg said in an exclusive interview with The Pantagraph Friday afternoon.

Marksteiner confessed to killing McGrew in a bedroom where his wife and three children were sleeping, according to a statement from McLean County prosecutors. McGrew was planning to baby-sit her three nephews the following day while her sister went to work at a LeRoy restaurant.

With answers will come justice, said Zogg.

"It's not done. As soon as I lay my daughter to rest, it's all about justice for Jodi. I will not stop until there's justice for Jodi," she said.

The Marksteiners had a troubled marriage in which Samantha suffering physical abuse, said Zogg, adding she encouraged her daughter to leave the relationship. Two orders of protection were issued but dropped against him after Samantha Marksteiner did not come to court.

She listened to her mother's comments Friday but offered few of her own. She described the sister who was one year and 12 days younger as a "my best friend. She was the comedian."

The two sisters were mistaken as twins growing up because they were so close and shared the same pretty, blonde looks.

"They held hands every step of the way. Samantha was her hero," said Zogg.

Zogg said she and her daughter were prescribed medication this week to help them deal with the tragedy.

The two-story home the Zogg family shares in Hallsville is filled with the Zogges' five children and two of their five grandchildren. The Marksteiner children remain with another relative in Department of Children and Family Services custody.

A table in a corner of the dining room is a makeshift memorial for McGrew, with photos, certificates of achievement from school and scrapbooks she made as gifts for her parents. Among the items on display is a handwritten letter McGrew wrote to the unborn daughter she named Mariah Noel.

McGrew's siblings also search for a reason behind their loss.

"She loved kids. I don't see why anyone would want to hurt her. I want to know why," said McGrew's brother, Jacob Zogg.

"She would have been a great mom," said Rachel Meade, another of McGrew's sisters.