Ravi Talware led a gang of masked men into the family home of John Jones before opening fire with a shotgun.
Mr Jones’ brother tried to escape but was stabbed multiple times at the home on Caslon Crescent, Stourbridge.
Talware shouted: “If anyone comes down the stairs, they are getting shot. If anyone rings the police, they are dead.”
The gang then fled in a getaway car, which was later found burned out less than two miles away in Gibbet Lane.
A murder investigation launched after the killing, which happened at around 7.30pm on 25 February last year, revealed Mr Jones owed around £180 to Talware.
A member of the public found a bag containing the weapons dumped in a bin in Wolverhampton the following morning.
Today, Talware was found guilty of murder, possession of a shotgun, possession of bladed articles and perverting the course of justice.
Kevin Waldron, who waited in the getaway car and then drove the gang away after, was convicted of the same charges, as was Scott Garrington.
Three youths, two aged 17 and one aged 16, were convicted of manslaughter, wounding, and possession of an imitation firearm as well as possession of bladed articles.
Det Insp Laura Harrison said: “This was an appallingly violent attack which left one man dead and another seriously injured, all over a relatively trivial sum of money.
“A lot of planning went into this attack and it was thanks to great detective work by officers who recovered CCTV and were able to piece together the killers’ movements that we’ve been able to get justice for Mr Jones’ family today.”
Sentencing will take place in June.
