Robert Price, 76, was tormented for years by local youths who harassed him and regularly broke the windows of his home in Dagenham, east London, until he finally barricaded them. Nathan Otitodilchukwu, 18, and a 16-year-old whose name cannot be disclosed for legal reasons, approached Mr. Price's home last July after filming them setting off fireworks into a lake. They entered the garden in front of the house, where the younger boy climbed on top of the gas meter box and punched a hole over the barricaded part of the window, then pushed a lit firework through it.