A New York prosecutor says a son of the late Sen. Robert F. Kennedy kicked a nurse to the floor as he tried take his newborn son out of a hospital without permission.

But a defense lawyer says Douglas Kennedy acted instinctively to protect the baby.

The lawyer says the nurse overreacted to an innocent attempt to get fresh air for the infant.

Monday's opening statements came in Kennedy's trial on charges of physical harassment and child endangerment.

The first witness, a hospital security chief, said the incident set off a hospital-wide "code pink" that indicates an abduction.

But he said that by the time he called police, he knew the baby was safely back in the maternity ward.