The Indiana Information Center on the Abolition of Capital Punishment (IICACP) exists to expose the injustice associated with the application of the death penalty in Indiana. IICACP is open to anyone who is opposed to the death penalty.
There are many excellent organizations working to end the injustice of the death penalty and this is by no means a complete list:

American Civil Liberties Union

Amnesty International

Campaign to End the Death Penalty

Citizens United for Alternatives to the Death Penalty

National Coalition to Abolish the Death Penalty

http://www.abolition.org

Murder Vicitms' Families for Human Rights

Death Penalty Discourse Center

www.deathofinnocents.org

Death Penalty Information Center

Indiana Public Defenders Council

www.deathrowspeaks.info

Notre Dame Against State Killing

Indiana Coalition Acting to Suspend Executions