The Genocide

First of all, the ill, old, disabled, and very young were forced out. If they were to choose not to go they would be murdered. If they didn't leave fast enough or wouldn't obey orders they would also be killed. The political and civil rights were banned. The army was killed as well. The intellectual people were killed together with their extended families. Religion was prohibited, especially Buddhism and almost all temples were thoroughly destroyed. Music and radios were prohibited.

This was a very cruel genocide. People would get killed for knowing something that the others didn't, such as a foreign language. People would get shot for simply laughing or even crying. The people who escaped the murders had to work almost all day and became unpaid labours. They slept and ate in communes and were given little food. Many would get so tired from over work and starvation that there was no medicine to help, so the only other choice for them was death.
Also, people were to not have relationships what-so-ever or expressions of affection.

Khemer Rouge targeted Chinese, Vietnamese, and Thai. They killed any Cambodian with the background of any of these ethnicities.