KENNER, La. (AP) — A 20-year-old woman accused of dropping her newborn baby girl into a lake told police she felt the infant’s heart beating as she let the child slip from her hands into the brackish water.

‘‘It’s hard to believe,’’ Kenner Police Chief Steve Caraway said on Wednesday. ‘‘This was a beautiful little girl, full term, a child that could have made someone very happy.’’

Ciara Craig, a sales clerk who lived in the New Orleans suburb of Metairie, will be charged with first-degree murder, Caraway said. Killing a child under 12 in Louisiana brings an automatic first-degree murder charge, which could result in the death penalty.