Two robbers had fled an Echo Park medical marijuana dispensary in 2010 with their loot — cash and $10,000 worth of marijuana. They even dismantled the security cameras.

But for no apparent reason, prosecutors said, they returned moments later and used a revolver to shoot two workers lying on the floor.

Matthew Butcher, a 27-year-old clerk, died from a single gunshot wound to the head. With two bullets lodged in his head, a bloody and disoriented Urban Jones Jr. managed to grab a dumbbell to break the glass door and stumble onto the sidewalk to get someone's attention. Jones, the dispensary's security guard, survived.

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On Friday, the two robbers were sentenced to life in prison without the possibility of parole.

"They're gone forever, and that's good," said Butcher's mother, Julie, standing alongside her son Steven at a post-sentencing toast in Matthew's honor.

A jury in November convicted South Los Angeles residents Raymond Lemone Easter, 31, and Daniel Deshawn Hinton, 35, of murder and attempted murder. Hinton had been going to the dispensary for several months; Butcher and Jones knew him as "Scooter."

That turned out to be Hinton's gang nickname. Since the age of 14, both Hinton and Easter had been in and out of custody, including convictions for possession of marijuana with intent to sell. Easter, the one who fired the shots inside the dispensary, also has convictions for bringing a knife to school and possession of a firearm.

Julie Butcher chronicled last year's trial and the impending sentencing through the social media hashtag #JusticeForMateo and started a foundation in her son's name "to encourage acts of kindness." On Friday, she reminisced to the court about her son's first words: "ball" and "dog."

"For a while, our little world was divided into balls and dogs. He was a sweet baby, a delightful child, smart, stubborn and inquisitive," said Butcher, the well-known Inland Region director for Local 721 of the Service Employees International Union.

"He'd give you the shirt off his back," she said. "There was no reason to kill him, there was no need to kill him."

Hinton and Easter claimed innocence at Friday's hearing in a downtown Los Angeles courtroom. Los Angeles County Superior Court Judge Stephen Marcus had to interrupt their statements to remind them that they had been convicted by jurors. Neither testified during the trial.

"Any murder is senseless, but this one was so much more," Marcus told the courtroom, calling the "sick, close-range ambush ... as cold a scene as I have ever seen in my 25 years as a judge."

paresh.dave@latimes.com