PAILIN, Cambodia — They have the blood of millions staining their souls, but for Christian missionaries that just makes the Khmer Rouge veterans better prospects for conversion.

The ultra-Maoists’ former stronghold of Pailin, the Cambodian town where they held out for almost two decades after a Vietnamese invasion ended their brutal regime in 1979, is now home to five churches. It is an incongruous statistic for a town peopled by atheists in what is a Buddhist country.

During their time in power, the Khmer Rouge killed an estimated 1.7 million people.

But church leader Phannith Roth’s message is simple: However hideous your sins, Jesus can cleanse you.

“Our purpose is to convert the Khmer Rouge to the Lord,” said the pastor of Pailin Bible Presbytery Church, which has 200 worshippers.

He cited the example of a former soldier. “Before he converted, every day his face was so low and his mind disturbed because he said he had guilt — he had committed something wrong under Pol Pot,” Phannith Roth said. “He confessed to killing a lot of people. Since he converted, he is happy and says his sins have been forgiven by the blood of Jesus.”

The pastor sees the establishment of a court this month to try the surviving Khmer Rouge leaders as an opportunity to spread the word of God. He has visited two of the likely accused, Pol Pot’s deputy, Nuon Chea, and the regime’s head of state, Khieu Samphan.

“We want to give them God’s love.We want to show them that when they go to the trial, what is the hope for them? Only God,” Mr. Roth said. “If they accept God, then they don’t need to worry because God will forgive them.”

The Good Samaritan Church, which was the first in the town, has five senior Khmer Rouge officials among its congregation.

Mey Meakk, a former secretary to Pol Pot who converted and is now one of the town’s deputy governors, estimates the Christians in and around Pailin at about 3,000.

“It’s better with a God,” he said. “A God will protect you if you do wrong.”

The director of information for the town, Kong Duong, converted in 2002. A radio broadcaster for the Khmer Rouge after the regime fell, he lived and worked with Pol Pot. He said he felt much calmer as a Christian.

“Believing in God and Pol Pot are a bit different,” Kong Duong said. “Believing in God is something you keep in your mind to live peacefully.

“I had to believe in Pol Pot. My father was killed by the Khmer Rouge, my sister had a rock tied around her waist and was drowned.”