Ms. Slemmer was killed in 1995 by Christa Pike, whose execution in Tennessee was botched on Wednesday. Her family celebrated what would have been her 51st birthday last month.

© Zack Wittman for The New York Times

May Martinez, who waited outside the prison for an execution that didn’t happen, said she could not fathom Christa Pike changing.

© Zack Wittman for The New York Times