A teenager who chased and killed a rival with the victim’s own knife has been jailed for at least 13 years.Christian Kuta-Dankwa, 19, of Rayners Lane, Harrow was jailed on Monday for life with a minimum term of 13 years for the murder of Mohamoud Mohamed Mahdi in Edgware in February last year.The Old Bailey heard how Kuta-Dankwa and his friends arrived in Watling Avenue, Burnt Oak on February 18 shortly before Mohammoud, 28, arrived on the opposite side of the road.