One demand that remained constant was for bulletproof vests. During early negotiations, one of the requested vests was exchanged for what was to be the release of nine hostages, although only three were released initially; the police officer who took the first vest to them stripped to his underwear to prove he was unarmed. Loi Nguyen sent a woman to retrieve the vest and threatened to shoot her children if she did not return; after she retrieved the vest, they were the first three hostages to be released. In addition to the hostage exchange, another benefit was that it allowed police to gain information on the current situation in the store. One of the released hostages revealed that the shots heard earlier had been the hostage takers shooting at the store's security cameras, and that none of the hostages had been harmed up to this point. Soon thereafter, more shots were heard, but this was the hostage takers testing the vest. Approximately an hour later, another woman and her three children were released; an eighth hostage was released at 8:20 p.m., bearing a message that they would start to shoot the other hostages shortly.