There have been many negative stories regarding Rio in terms of security. Rio will most certainly earn a bad reputation if things like this continue. The Olympics are supposed to be a time of solidarity and international sportsmanship. Theft of athletes' belongings will only increase disparities and conflicts within countries.
Economic and political turmoil aside, Brazil has come a long way in the past few decades, and the leadup to the Rio Olympics are doing a lot to eliminate that goodwill. The number of horror stories coming out of the city from Olympics athletes suggest it might just be better to cancel the games altogether.
Rio will be chaotic before and during the Olympics, and there will be many reports about it. This is because there are a lot of problems with things such as the crime rate, proper accommodations, and water pollution. It is too late for the government of Brazil to address these issues properly now.
With all of the negative news stories prior to the Olympics, I think that Rio's reputation is already pretty bad. Barring some disastrous event happening during the Olympics, I think the event can only help the city's image. That is what seems to happen to the host city/country during every Olympics.