import flash.utils.getDefinitionByName;
import flash.utils.getQualifiedClassName;

public function getNewClassInstance(object:*):*{

	var className:String = getQualifiedClassName(object);
	var classReference:Class = getDefinitionByName(className) as Class;
	var newClassInstance:* = new classReference();
			
	// e.g. object is from the class MovieClip

	trace(newClassInstance); 	// [object MovieClip]
	trace(className);		// flash.display::MovieClip
	trace(classReference);		// [class MovieClip]

	return newClassInstance;
}

This function returns a new instance of the class it receives.

Returns a new object of the same Class

class, object, copy

ActionScript 3