Florida executed death row inmate Duane Owen by lethal injection on Thursday evening, nearly four decades after he murdered a 14-year-old babysitter and a single mother of two in separate attacks.

Owen was convicted for the 1984 rape and fatal stabbing of teenager Karen Slattery and for the rape and killing of 38-year-old Georgianna Worden in Palm Beach County.

Owen declined to make a final statement, according to CNN affiliate WPBF.

Family members of the victims were present for the execution. After it was over, Slattery's younger sister, Debbi Johnson, said the family may now close Karen's book, put it on a shelf and move forward.

"He didn't open his eyes. I know because I looked at them," Johnson said at a news conference. "He made no statement -- no verbal statement anyway. He died with dignity, and unfortunately his victims did not."

Johnson, who is now a deputy sheriff in Florida's Monroe County, was 10 years old when her older sister was killed.

"With this rain today, I was really hoping I was going to see a rainbow. Because that's what my mom always said: 'Whenever you see a rainbow, that's Karen smiling down on us,'" Johnson said.

Slattery was repeatedly stabbed and raped in a home in Delray Beach while the two children she was babysitting were sleeping.

And two months later, Owen killed Worden of Boca Raton with a hammer, while her two small children slept nearby, according to WPBF.

Owen had been on death row since his convictions, and despite decades of appeals and insanity defenses, Gov. Ron DeSantis signed his death warrant this year, according to CNN affiliate WPBF.

For his last meal, Owen requested a bacon cheeseburger -- no bun -- in addition to onion rings, strawberries, cherry ice cream, a vanilla milkshake and a coffee, according to the state's Department of Corrections.

Johnson said the authorities' response to her sister's case and the work officers put into it inspired her to go into law enforcement.

"Closure may be a myth, but justice isn't," Johnson said.

"Thirty-nine years and this process is finally over," she added. "He served his sentence. The end."

Owen is the fourth inmate to be executed in the state this year. Florida is one of 27 states where the death penalty remains in place, according to the Death Penalty Information Center. Three of those states have governor-imposed moratoriums.