McGinn, 43, convicted of raping and bludgeoning with an ax his 12-year-old stepdaughter, was twice before scheduled to die.
An execution date set for earlier this year was postponed after some of his paperwork was lost when a tornado struck his attorney's Fort Worth office.
Then on June 1, only moments before he could have been put to death, Gov. George. W. Bush for the first time used his gubernatorial authority to issue a one-time, 30-day reprieve for McGinn so additional DNA tests could be run on evidence in his case.
When the test results completed in August again linked McGinn to the crime, the execution was reset for Wednesday.
In a final statement, McGinn said, "Tell everybody I said hi, that I love them, and I will see them on the other side, OK? And now I just pray that if there is anything against me that God takes it home. I don't want nobody to be mad at nobody. I don't want nobody to be bitter. Keep clean hearts and I will see y'all on the other side."
He smiled to his family, many of whom were sobbing, and then sputtered as the drugs began taking effect. There was no reaction from family members of the victim.
He groaned slightly and then his eyes closed. McGinn was pronounced dead at 6:22 p.m. CDT, eight minutes after the lethal drugs began taking effect.
Bush's reprieve, in the midst of his bid for the Republican presidential nomination, was viewed as an example of his compassionate conservatism, a favorite campaign theme.
It also reflected a concern about death penalty convictions that developed since Illinois Governor George Ryan, a Republican death penalty supporter, declared a moratorium on executions after DNA evidence spared 13 men from his state's death chamber.
McGinn said he appreciated the reprieve but also accused the governor of using his case for political gain.
The new DNA tests on crime scene evidence supported Brown County authorities who said McGinn killed Stephanie Flanary on May 22, 1993, and dumped her body in a culvert where it was found three days later.
"Certainly it helps to have that reconfirmed in even stronger terms," said Brown County District Attorney Lee Haney, who prosecuted McGinn. "I think everyone involved in the case right now is just looking for a sense of closure."
Despite the test results, McGinn continued to deny any involvement in the girl's death.
"I still want the world to know I'm not guilty," he said. "Somebody else put that there. I know they did it and they know they did it."
Haney said McGinn's contentions that evidence was planted or tampered with were unfounded.
"He already had that claim lined up before this all started," Haney said.
McGinn's ife had left her daughter in his care while she left for the day. McGinn said the girl got sick after they drank beer together and dozed off, then went for a walk after waking up. She never returned.
Blood evidence tied him to her rape and slaying. A jury also heard from three other sexual assault victims, including one who said she was attacked by him when she was a pre-schooler.
McGinn was the 33rd convicted killer to receive lethal injection in Texas this year. The state has executed 232 since 1982. Seven more executions are scheduled before the end of the year, which would bring the yearly total to 40, a record eclipsing the previous mark of 37 set in 1997. 144 executions have taken place on Bush's watch.
In his final days, McGinn signaled an acceptance of his fate.
"I'm ready to go," McGinn had said in an earlier interview. "I guess I'm just tired."
"I'm tired of living the way I'm living," McGinn said. "Any way I leave here, I'm going to be better off."