A widow who cleaned houses broke down in court, telling how she spent her husband’s death payments on heroin. There was a gymnast who became hooked on prescription painkillers after an injury. One young man said his path to addiction began by taking his parents’ cancer pills. Then came an auto-parts dealer, the girlfriend of a dairy farmer, a man with multiple sclerosis. They told how their use of prescription painkillers such as Percocet and Oxycontin led to a cheaper substitute of heroin.