The jury rejected Kisharne "Kash" Campbell's claim he had only meant to shoot a warning shot at the taxi carrying Kimani Martin on June 20 last year, and convicted him of murder.
After deliberating for 25 hours and five minutes about the guilt of those in the car from which the fatal shot was fired, they also found Atif Khan guilty of murder and Usman Amjad guilty of manslaughter. Another defendent, Luke Adams, was cleared of murder.
The four-week trial shone a light on the murky world of drug dealing and "drill music", and how they combine to create a lethal cocktail of bravado, violence and gang disputes.
Campbell released music on Spotify, Apple Music and Soundcloud under the name Kash, boasting about his drug-dealing empire and violence meted out to rivals.
He filmed videos in Tipton riding around in a Rolls Royce bragging about how much crack and heroin he sold, how he would cut the drugs to make more money and his readiness to use a gun if needed.
Campbell was invited to record a song and video for urban media platform P110 which helped Jaykae, Skepta, Mist, Giggs and Bugzy Malone on the path to mainstream stardom.
In the video for P110's Hood's Hottest 2, the 23-year-old can be seen getting out of a Rolls Royce wearing his distinctive "Kash" gold and diamond necklace.
Filmed at Dudley Port hand car wash and valet, the video featured a luxury BMW, Mercedes and expensive quad bikes. Surrounded by masked men drinking brandy Kash immediately boasts about his burgeoning drug empire.
His opening line being: "I put the food on the scales and tell my young boy to wrap it up" and also raps about "mountains of snow (cocaine) and "reloading half a b (kilo)".
Mimicking shooting a gun Campbell warns he happily will enter drug rivals' "trap houses" and " still kidnaps and do acid attacks".
The trial at Birmingham Crown Court heard how Aston teenager Kimani Martin befriended Campbell at a music studio. Then, after arranging to meet Campbell for a drug deal, he kidnapped him and Luke Adams at gunpoint, forcing them to hand over money and a mobile phone with a "drugs hotline" as its number.
Mr Martin and his two associates also stole Campbell's "Kash" necklace.
An associate of Kimani Martin, who did not want to be named, told the Express & Star: "Kimani loved having a laugh and he would have been showing off the necklace on Snapchat as soon as he could.
"He was only 18. No-one deserved to be murdered. What happened to him has made a lot of us grow up and look at our lives."
The necklace was found in the back of the taxi in which Kimani was shot dead, and provided detectives with their first major lead in the investigation.
Detective Inspector Jim Colclough, from West Midlands Police Homicide Squad, said: "With the necklace in the back of the taxi was Campbell's mobile phone, so we rang his mother and spoke to her to find out his whereabouts.
"We quickly realised Campbell was central to our investigation. It did not take long to identify the other three but we had to be patient with Khan who fled to Pakistan after the murder and we had to wait until he returned to the UK to arrest him."
He added: "We never did track down the two people with Kimani in that taxi. However, they are lucky to be alive because we believe those in the car acted together.
"We know after the first shot, the Golf circled around and the driver asked the taxi driver where the other two were. We could easily have been dealing with a triple murder."
He added: "We charged all four with murder under join enterprise because they would have knew Campbell wanted revenge. Whilst in the Golf several calls were made to 1-2-1 Cars to try and locate the taxi which had picked Martin up. We don't believe they were given any information but they tragically spotted the taxi leaving Tipton and gave chase.
"They knew he had a gun, this was not a revolver hidden in his pocket which he pulled out seconds before the shooting. He had a shotgun which have long barrels, they would have all seen him and were encouraging him to use it"
In a chilling boast which foreshadowed future events, Kash raps "He always keeps a strap (gun) close to him".
During the trial the jury heard that within an hour of being freed by his captors Campbell had a loaded shotgun in his hands and was ready to kill.
Campbell being taken off the streets gave particular satisfaction to detectives in the West Midlands Police, whom the rapper regularly goaded in his music and videos.
Smiling at the camera he taunts: "Drugs squad from my teens still trying to raid me.
"Drugs squad trying to find out where ****** at, I'm up at Harvey Nicks about to spend two wraps (£2,000)."
DI Colclough said: "Clearly you can see Campbell was a danger to society. He no regard for the law and a total disregard for human life. If crossed he was willing to exact fatal revenge."
The homicide squad, which is now comprised of detectives and civilians, built watertight case against Campbell.
One civilian who worked on the case is a former detective who left the force after serving 30 years but has returned to offer his expertise in a civilian capacity. The 70-year-old cut his teeth in the force before DNA, mobile phones and motion sensor cameras were even invented but his people skills and insight makes him a valuable asset to the team. .
Trawling through CCTV footage, which had to be recovered from homes and businesses across Tipton, Dudley Port and Tividale, they created a visual timeline comprised of hundreds of pictures and video clips of showing Campbell from when he was let go by Martin, releasing Adams from a car boot all the way through to fleeing from the Golf carrying the shotgun in a rucksack.
Officers even managed to find a camera which captured the fatal gunshot
The 23-year-old lied for 11 months about his role in the shooting by continually claiming there was a fifth person in the car who shot Kimani.
However, in a remarkable turn of events during cross-examination by Khan's lawyer Campbell admitted being the shooter after fellow defendants refused to back up his lies.
The cocky bravado of his persona as a rapping drug kingpin living the fast life crumbled in the dock as he began crying when confronted with the tragic consequences of his actions.
Campbell's admission even surprised his legal team, his defence barrister Stan Reiz QC told the jury he had been misled, and then entered a plea of manslaughter which prosecutors rejected immediately.
The jury made short work of Campbell's guilt as a murderer but then had to decide whether the other occupants of the VW Golf were an execution squad or confused young men in the wrong place at the wrong time.
Adams, 19, from Walsall, who had been kidnapped, told the jury he had no idea Campbell would murder Martin and was discharged from custody.
Campbell, and Usman Amjad, 22, both of no fixed address, and Atif Khan, 25, from Park Lane, Tipton, will be sentenced on Wednesday, June 29.