Donald Moeller was put to death by the state Tuesday night for raping and murdering 9-year-old Becky O'Connel more than 20 years ago.
The lethal injection was administered at 10:01 central time, and he was pronounced dead 23 minutes later.
Before the drug entered his system, Moeller declined to make a final statement, but asked the warden, "They're my fan club?" referring to the people observing.
An Associated Press reporter who was present said Moeller took about eight deep breaths and turned a pinkish color soon after.
"And then he started turning ash a little bit and then a purple tint," Kristi Eaton, the AP reporter, told journalists after the execution, "and then later on the coroner came in and took his vital signs."
Moeller was pronounced dead at 10:24 central time.
After he was pronounced dead, Becky's family showed pictures of the girl while her father read a statement.
In it, he said Moeller's death did bring the family some relief, but nothing could ever provide closure.
"Donald Moeller not only took Becky's life - savagely, I might add - he also took ours," Becky's father said. "We despise that so-called man."
Several dozen people congregated outside the prison during the execution to protest the death penalty.