But when security searched her bag, they made a horrifying discovery.
The teenager was today charged with second degree murder over the incident.
She has pleaded not guilty but her lawyers claim the baby was stillbirth – and not murdered.
But prosecutor Rachel Ferrari said: "[Rodriguez] carried out the murder of her newborn infant and then callously shoved him in a bag with the plan of – in her words – 'take this s*** and dig a hole, put it somewhere, then we go eat International House of Pancakes.'"
The teen mum, from Brooklyn, US, is thought to have fallen pregnant in early 2013 – but worried her family would find out.
She gave birth at a friend's house in October 16 2013 and "ripped the cord with her bare hands".
Ferrari added: "He wasn't stillborn, he didn't die of natural causes. He was murdered in that bathroom."
Rodriguez is then accused of stuffing the baby's body into a shopping bag and setting out to dispose of it.
The shoplifting case collapsed last year when time ran out to try it before a court.
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