By Dana Kozlov

(CBS) — A woman who watched her ex-fiancée allegedly kill three members of her family testified in court Wednesday.

28-year-old Amanda Engelhardt was the first witness in the murder trial of D’Andre Howard, charged with killing her father, sister and grandmother in 2009.

CBS 2’s Dana Kozlov reports the case isn’t about if Howard killed his fiancées relatives, it’s about his state of mind at the time, with defense attorneys asking the jury to find him not guilty by reason of insanity.

Prosecutors told jurors during opening statements he turned that quiet home in Hoffman Estates into a house of horrors in the early morning hours of April 17 2009. They say 25-year-old D’Andre Howard began stabbing members of fiancée Amanda Engelhardt’s family in what they suggest was a methodical fit of rage. Then Amanda took the stand, giving her eyewitness account. Her brother Jeff sat in court for it all.

“I am really proud of her. She was really brave and I know it is tough for her,” said Jeff Engelhardt.

Amanda described how Howard, brandishing that butcher knife, first tied her and her mother Shelly up together with knitting yarn, before waking and then tying up her 18-year-old sister Laura. Then, when Laura later grabbed the knife and stabbed Howard in the arm, Amanda said he unleashed, stabbing Laura repeatedly in the chest, moving next to Shelly, then Amanda’s 73-year-old grandmother and finally to her father Alan.

Shelly Engelhardt survived while the others died. Engelhardt also testified, recounting how, in and out of consciousness, she remembers hearing cries to stop.

But Howard’s public defender says he’s mentally ill, calling this a tragedy.

“Mental illness,” she told jurors, “kept him from being able to appreciate the criminality of what he had done.”

Watch & Listen LIVE