He is a fiery and outspoken advocate of the abolition of the death penalty and for a fair and just judicial system. He wrote, directed and produced a one-man play, "Dead Wrong," "Death Row Blues." As songwriter, harmonica player and singer he produced a CD about his death row experience and his life afterwards called "Death To Life." In an interview in the April 2007 publication of the New Abolitionist asked about his inspiration he answers, "Each day, I look for a different twist as to how to expose the horrors of death row and the flawed system to the public. My CD was singing. The play is singing and dramatizing the pain and the hurt that was done to me by the system. It's another way of opening the door for people to peep into this painful ordeal."

In 2006 Tillis played the role of Stanley Tookie Williams in a reenactment of a botched execution that led to California's moratorium on the basis of cruel and unusual punishment. In 2007 Tillis testified before the Senate Finance Committee in in support of an abolition bill in Illinois saying "The time to abolish the death penalty is now!" In November, 2007 he joined with 17 death row exonerees in Raleigh, N.C. in a call for a moratorium on executions in that state.

He has preached, worked and walked among gang members and drug abusers, fed the homeless and helped the fallen and oppressed as founder and director of WXO.FM, working with Ex-offenders and Family Members. He continues to speak throughout the country at colleges, to youth groups, churches and abolition groups. Most recently, he will begin a Death Row Shuffle Tour speaking and singing in high schools to youth groups in communities impacted by the criminal justice system through a grant (Fire This Time Fund 2008 Funded Project) with the Campaign To End The Death Penalty. "The hope is that youth will learn from Darby's personal experience, songs and storytelling and feel empowered to organize themselves and as agents of social change."