As the Target murder trial continues in Gwinnett County, prosecutors play a dramatic recorded phone call from son to accused-killer mother.

In the call, played for jurors Monday, Steven Strube says he's just seen surveillance video of his estranged wife's murder.

"Mom, why did you do it?" a weeping Strube accuses his mother.  "Mom, that looks like you.  It looks just like like you.  Walks like you."

Joanna Hayes replies, "I didn't."

Heather Strube was shot in the head after the young mother had just exchanged custody of her 18-month-old son with her estranged husband. Joanna Hayes, then 46, was arrested six months after the murder.

Earlier Monday, a young girl testified she actually saw and heard the shooting--and could tell the shooter was wearing a disguise.

"I had noticed a person in a weird-looking wig or a costumer of some sort," testied Kiersten Rom.

Later she says she saw that person reach for a "big black case".  Soon there was a "popping noise, and then the woman that was standing by the car collapsed."

But on defense cross-examination, Rom admitted she'd ben unable to pick Hayes out of a police lineup, later.

Police say surveillance video from the scene shows Hayes wearing a wig and fake mustache. She owns a white pickup that police say was spotted parked behind the Target at the time of the murder.

Hayes' son and Strube were in the last stages of a bitter divorce at the time. In opening statements, prosecutors maintained Hayes didn't want custody of her grandson to go to Strube.

Jurors may hear from Hayes' soon this afternoon.

But Hayes' attorney Bruce Morriss maintains police focused on Hayes early on in the investigation and never looked for other suspects.

The trial may last another three weeks.