Well okay, but murder is murder, right? I would think that if Ahmadinejad actually believes there are no homosexuals in Iran, and if some teenage zealots murdered someone because they claimed the person was gay, he would be extra sure that the young men were prosecuted.
Human Rights Watch is a VERY credible source. I would take them at their word.
This is very disturbing about the Fundamentalist Muslim control of Iranian society. I had though that such conduct was limited to such countries as Iraq and Afghanistan.