In 2005, he was in an argument with a man who ended up dead the next day. He said the man's friends suspected he was responsible, and one day, while Johnson was involved in a drug transaction, he was ambushed as he tried to run into his apartment.
Four bullets struck him. They broke his left femur and pierced his right forearm, foot and right leg. He underwent surgery and had plates and rods inserted in his leg, leaving him with leg-length scars and pain he routinely tries to beat back with Motrin.
But the near-death experience didn't change him, he said. He dealt drugs on crutches, hobbling from car to corner, until the police caught him again. He stood in front of the judge on crutches.
The judge took note that arrests and bullets didn't seem to be enough to reform Johnson, so he sent him to prison for 20 years.
He saw the shooter a few months ago when he cruised by a corner. The man wasn't charged in the shooting; Johnson had refused to "snitch." Still, for years, he had contemplated revenge.
But something was different. He felt at peace, he said.
"He turned around and saw my face, and I saw his," Johnson said. "I knew right there I had changed."
Those who have watched Johnson over the past year point to his willingness to work on his anger as another factor in his success.
"A change must be made or else they will not survive," said Derek Neal, one of Johnson's caseworkers. "It's that desire to live again that brings people to a realization. With Clifton, [it was] 'How many times am I going through the same cycle? How many times am I going to get shot? How many times am I going to stand in front of a judge? It's time for a change.'"
The apartment complex where Johnson was shot no longer exists. It's now a parking lot. So too with the buildings on much of the block of Thomas Avenue where he grew up, replaced by new construction and cranes expanding Coppin State University.
"All of it's erased away," he said. "So I look at it like something good. Where I got shot at. The block where I was born and did all my dirt at. All of it's washed away."
Driving past the Can Do Fuel Oil Co. on Baker Street, he spotted an old friend. He slowed, and the pair exchanged pleasantries. Before Johnson moved on, the man yelled out, "Proud of you, Man. I know where you came from. You keep up the good work."
Johnson smiled, embarrassed but proud. He feeds off the affirmation and said he seeks out the "good vibes," choosing these days to associate himself only with positive influences — another reason he says he will not return to crime.
One of those influences is the Rev. Keith Bailey, whom Johnson often visits in the 1800 block of W. North Ave.. Bailey operates a food pantry and soup kitchen with the help of parolees who want to work off community service requirements. That's how he met Johnson, who showed up "every day on time." He now refers to him as his "godson."
"Some of the volunteers that come, they have their little problems, but they're not dedicated," he said. "They don't want to change. Then you got Cliff. He wanted to make a change in his life."
That realization came during his last stint in prison.
He watched older inmates limping around their cells with canes and understood a truism of the street: There are no old drug dealers.
"Two things are certain in this rough city in the drug game: prison or the graveyard," he said. "I was just thinking of how I was growing old in there, how I'd been there since I was 14. Man, I'm 40-something."
His grandmother's death in 2011 also played a role. She raised him, but he couldn't be at her side when she died because he was behind bars. He learned about her death from a niece, who visited him with tissues in her hand.
"I just wish my grandmother was living to see," he said. "She told me I needed to get my life together, and I did."
At the end of the day, he drove toward home. He lives in the Woodlawn neighborhood with his girlfriend in an immaculate home with porcelain cats and leather couches and a mantel filled with photos that include one of his girlfriend's nephew, who was fatally shot a few years ago, another victim of Baltimore's streets.
The home has the trappings of a middle-class family. It's a far cry from where he envisioned himself when he was flashing cash and selling "weight" or large amounts of drugs to street dealers that brought him about $5,000 a day, he said. But that's all right.
"I work, she works, so we're good," he said. "This is the first time I have everything legitimately."
He is proud of the credit cards he keeps in his pocket because he is establishing credit for the first time. He hopes to one day buy houses and start a transitional housing service for ex-offenders like himself. While his job doesn't pay as much as crime did, he's proud of his job title, bragging that he is "chief coordinator."
"I'm on top of the other coordinators," he said. "I'm like the boss."
For the first time, he said, he feels in control of his life. He isn't looking over his shoulder for bullets or police — just at all he says he's left behind.
"I just keep it moving," he said.