A factory supervisor died after being stabbed more than 100 times by two youths wielding a samurai sword, a court has heard.
Robert Wilson, 53, was attacked after he asked the pair to leave the car park of a factory in Huddersfield on 16 January, Leeds Crown Court was told.
Kiyran Earnshaw, 18, and Luke Gaukroger, 16, both admitted murder.
Earnshaw was jailed for a minimum of 22 years and Gaukroger was ordered to serve 16 years and eight months.
Mr Justice Lavender said both youths had been heavily intoxicated at the time they had carried out the "frenzied and senseless attack".
He said Mr Wilson had done them "no wrong".
Peter Makepeace QC, prosecuting, earlier told the court the youths had been seen in the factory car park and Mr Wilson, from Birstall, and two other colleagues went to move them on.
At one point Mr Wilson put his phone to his ear to talk to the remote security firm, and Earnshaw started shouting at him, claiming he was being filmed.
'Pass the shank'
He then pulled a samurai sword from his trousers and pursued Mr Wilson as and he and his colleagues tried to get away.
Audio of the attack, caught on Mr Wilson's phone by the security company, was played in which Gaukroger, who was 15 at the time, demanded the sword at one point saying: "Pass me the shank, pass me the shank."
Earnshaw inflicted multiple blows and kicks to Mr Wilson before he passed the weapon to Gaukroger who then also inflicted a number of severe blows.
Mr Wilson died at the scene, despite efforts by police and paramedics to save him.
A post-mortem examination revealed "at least 100 sharp force injuries to the body" in the region of the head, neck and upper body.
'Much admired man'
Mr Wilson's wife, Elaine, said in her impact statement that her husband's death had been "soul-destroying".
Mrs Wilson told the defendants: "I want you to know you have taken the life of a much respected and admired man."
She said to receive a letter from one of them saying it was "the worst night of my life" and "I'm sorry" had sickened her.
"It has shocked me to realise I have such hate," she added.
Mr Wilson's colleague, John Badejo, was also injured in the attack. Earnshaw admitted wounding with intent and was jailed for nine years to run concurrently with his murder sentence.