Prosecutors say a teenager suffocated her just-born baby before taking his body with her on a trip to Victoria's Secret in New York City.

Eighteen-year-old Tiona Rodriguez pleaded not guilty Thursday to a murder charge stemming from the shopping trip two years ago. Prosecutors say she was arrested on a shoplifting charge at the store, and her 8-pound newborn was found dead in a bag she was carrying. The shoplifting charge was later dropped.

Prosecutors say Rodriguez intended for weeks to kill the infant and sent a text message about plans to "dig a hole" and "put it somewhere."

Defense lawyer Earl Ward says Rodriguez's term of pregnancy was unclear. He says Rodriguez didn't know she was pregnant and she had a stillbirth. He says she acted out of confusion.