This paper reports on some new results from the analyses of the video microscopy data obtained in a prior
experiment on two-dimensional (2D) colloidal crystals. It was reported previously that optical tweezers can be used
to create mono- and di-vacancies in a 2D colloidal crystal. Here we report the results on the creation of a vacancyinterstitial
pair, as well as tri-vacancies. It is found the vacancy-interstitial pair can be long-lived, but they do
annihilate each other. The behavior of tri-vacancies is most intriguing, as it fluctuates between a configuration of
bound pairs of dislocations and that of a locally amorphous state. The relevance of this observation to the issue of
the nature of 2D melting is discussed.