A 17-year-old has been given life imprisonment for killing a man in Ipswich.
Kieran Hayward, from Hasted Close in Bury St Edmunds, stabbed Daniel Saunders after selling him drugs on December 16 2018.
The attack happened in an alleyway behind Turin Street; Saunders, who was 32 and originally from Surrey, was able to stagger to Kenyon Street but died there.
A post-mortem examination found that Hayward had used a foot-long blade to stab Saunders, causing massive blood loss.
Speaking after the sentencing, Suffolk Police said the murder demonstrated how deadly drug dealing can be.
Detective Chief Inspector Caroline Millar, the Senior Investigating Officer, said: "The sentences handed down today reflect the severity of the crime and I hope will allow Daniel Saunders’ family to now begin the slow process of moving forward with their lives.
"This was a fast-moving investigation from the very beginning and due to the hard work of all the officers and staff involved, we were very quickly able to identify Kieran Hayward as the prime suspect for the murder.
"Everyone involved with investigating this case worked extremely hard to enable us to gather all the evidence, make further arrests, bring charges and be ready to go to trial all in the space of sixth months, which was no easy task.
"Daniel’s murder was an act of extreme violence and has once again demonstrated how dangerous the world of drug-dealing is and which has seemingly become more violent since the advent of county lines."
Hayward was involved in a drug dealing operation called 'Rico and Frank' at the time of the stabbing.
In the days following the attack he was helped by several associates, and five people have been convicted of assisting an offender in connection with the murder.
As well as Hayward's life sentence, of which he'll serve a minimum of 19 years, four others were sentenced on Monday.
Benjamin Gosbell, 20, of Gratian Close in Colchester: sentenced to 30 months in jail.
Arjun Jadeja, 18, of The Nook in Wivenhoe: sentenced to 30 months in a Young Offender Institution.
Kieran Elliott, 17 of Stanford Road in Colchester: sentenced to an 18-month detention and training order.
Olusola Durojaiye, 33, of Appleton Mews in Colchester: sentenced to 12 months in jail, suspended for two years.
A 16-year-old boy from Bury St Edmunds, who was also convicted of assisting an offender, will be sentenced on October 25.
He was detained alongside Hayward, Jadeja and Elliott just four days after the stabbing at a caravan park in St Osyth. Gosbell and Durojaiye were arrested in January in Colchester.
DCI Millar added: "Suffolk Police continues to do all it can to tackle the evil world of drugs supply and the associated knife crime that often goes with it, as too many families are being left to pick up the pieces of the devastation it causes.
"If you believe someone you know may be getting drawn into this world there is help available from a number of support agencies, the details of which can be found on the Suffolk Police website, as well as that of Suffolk County Council and local authorities.”