A man has been charged with murder over the one-punch assault of 18-year-old Daniel Christie in Kings Cross on New Year's Eve.

Shaun McNeil, a 25-year-old builder, will face court today charged with murder after Mr Christie's life support was turned off on Saturday.

McNeil had already been charged with three counts of common assault, assault occasioning actual bodily harm and assault occasioning grievous bodily harm over a series of alleged assaults on New Year's Eve.

Mr Christie had been in a critical condition for 11 days before his family made the decision to turn off his life support.

Following his death, NSW Attorney-General Greg Smith had asked the acting director of public prosecutions to closely examine the case with a view to determining if murder charges were appropriate.

Prosecutors will have to prove McNeil intended to kill Mr Christie or that he acted with reckless indifference to human life.

He could face life in prison if the case is proven.

Christie family donates organs after death

Daniel Christie, 18, died at the weekend after being punched on New Year's Eve. ( Supplied )

The Christie family decided to donate Daniel's organs, saying they hope something positive can come out of his death.

"We believe there is no better way of honouring Daniel's generous and giving spirit than by donating his organs," they said in a statement.

The Christie family have spoken out against the use of the term "king hit" when referring to assaults, saying "coward punch" is more appropriate.

"We do not want Daniel's death to be in vain and are committed to rallying for change," the statement said.

"A positive change needs to come from such a negative situation.

"We would like 'coward punches' to be a thing of the past.

"People have the right to go out without experiencing mindless violence."