A Texas man convicted of beating and suffocating a Dallas area pastor in his church during a robbery was put to death Wednesday evening, the second execution in the U.S. this year and the first of four scheduled in Texas over the next three months.

The pastor's young widow, Laura Dobson, sobbed on the stand during Steven Nelson's murder trial, saying: 'I didn't know this much evil existed in the world.'

Steven Lawayne Nelson has maintained that while he participated unknowingly in a violent church robbery, he did not harm anyone.