Chaos erupted outside Texas' death chamber when the son of a condemned inmate became aggressive, shouted obscenities and threw fists after his father spoke his final words.
Billie Wayne Coble, a Vietnam War veteran who killed his estranged wife's parents and brother - and threatened to do the same to her in 1989, told the five witnesses he selected to attend his execution that he loved them.
Coble nodded at them as they watched from the witness room, adding: "Take care."
When he finished speaking, his son, a friend and a daughter-in-law became emotional, throwing fists and kicking at others in the death chamber witness area.
Officers stepped in but the witnesses continued to resist, and were eventually moved to a courtyard where the two men were handcuffed. They were arrested on charges of resisting an officer.
"Why are you doing this?" the woman asked. "They just killed his daddy."
As the men were being subdued outside, a single dose of pentobarbital was being administered to Coble.
The 70-year-old was the oldest inmate executed by Texas since the state resumed carrying out capital punishment in 1982.
He was convicted three decades ago over the 1989 shooting deaths of Robert and Zelda Vicha, and their son, Bobby Vicha, at separate homes in Axtell, which is north east of Waco.
Prosecutors once described Coble as having "a heart full of scorpions".
Coble, distraught over his pending divorce, kidnapped his wife, Karen Vicha. He was arrested and later freed on bond. Nine days after the kidnapping, Coble went to her home, where he handcuffed and tied up her three daughters and nephew, JR Vicha, according to investigators.
Coble then went to the homes of Robert and Zelda Vicha, 64 and 60 respectively, and Bobby Vicha, 39, who lived nearby, and fatally shot them.
After Karen Vicha returned home, Coble abducted her. He drove away, assaulted her and threatened to rape and kill her. He was arrested after wrecking the vehicle in neighbouring Bosque County following a police chase.
Coble was convicted of capital murder in 1990. An appeals court ordered a new trial on punishment in 2007, but a second jury also sentenced him to death.
On Thursday, the US Supreme Court turned down Coble's request to delay his execution. His attorneys had argued that Coble's original trial lawyers were negligent for conceding his guilt by failing to present an insanity defence.
The Texas Board of Pardons and Paroles also turned down his request for a commutation.