His crusade has taken him before Congress and audiences across the country. On Thursday, it took him to Terre Haute, home of the federal prison where McVeigh sits in a cell, awaiting his execution on May 16.
Everywhere Welch goes, the 61-year-old gas station owner delivers the same message: "There's no healing from killing people."
It is much different from how he felt at the time of the bombing of the Alfred P. Murrah Federal Building, the deadliest act of terrorism on U.S. soil. The 168 people killed included Julie-Marie Welch, a Spanish interpreter for the Social Security Administration.
"Julie was my best friend, my pal, my sidekick. We hung out together all the time," Welch said.
Welch felt only rage and sought only vengeance toward McVeigh and Terry Nichols, the two men convicted in the bombing. "I just wanted them fried," he said.
He brought his drinking under control. He quit smoking in 1998. Most of all, he started talking about forgiveness. And as news of his stance spread, people wanted to hear him.
Welch recalled television footage of Bill McVeigh, the bomber's father. "I could see quite a large man who was stooped in grief. I could see the pain in hi eye," Welch said. "I recognized the pain because I was going through it."
Welch was invited to speak in upstate New York and allowed a nun to arrange a visit with Bill McVeigh and his daughter Jennifer. As the two men discussed Bill McVeigh's garden, they found common ground. The two Irishmen had been raised Catholic.
Welch couldn't take his eyes off a picture of Timothy McVeigh hanging on a wall. "I said, God, what a good-looking kid," Welch recalled.
A tear formed in Bill McVeigh's eye.
"What I found that morning in western New York was a bigger victim than myself," Welch said.
He put his arms around Jennifer McVeigh and hugged her.
"I said, honey, the three of us are in this for the rest of our lives," Welch said.
Later that night, Welch sobbed.
"It was like all of this tremendous weight had been removed from my shoulders," Welch said. "I never felt closer to God than I did at that moment."
Executing McVeigh would only hurt more people, Welch said: "We're going to victimize another family now, people who are innocent."
Welch said relatives of some of McVeigh's other victims probably resent his message of forgiveness.
About 250 people who were injured or lost loved ones in the bombing have told the government they want to see McVeigh take his last breath. As a result, the government is considering a closed-circuit TV broadcast of the execution by lethal injection.
"They think they'll get some type of healing," Welch said. "There's nothing about killing that's going to help them."
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