As overdose deaths mount, prosecutors are increasingly treating them as homicide scenes and looking to hold someone criminally accountable. Using laws devised to go after drug dealers, they are charging friends, partners and siblings. The accused include young people who shared drugs at a party and a son who gave his mother heroin after her pain medication had been cut off. Many are fellow users, themselves struggling with addiction.

Such cases are becoming more common even as the role of the criminal justice system in combating drug abuse has become hotly contested, and even as many prosecutors — including those who pursue overdose death cases — say they embrace the push to treat addiction as a public health crisis rather than a crime.

Overdose prosecutions, they say, are simply one tool in a box that should include prevention and treatment. But there is no consensus on their purpose. Some believe they will reduce the flow of drugs into their communities, deter drug use or help those with addiction “hit bottom.” To others, the cases are not meant to achieve public policy goals, but as a balm for grieving families or punishment for a callous act.

“I look at it in a real micro way,” said Pete Orput, the chief prosecutor in Washington County outside Minneapolis. “You owe me for that dead kid.”

Who owes whom for what is less clear in the case of the Malcolm family in Breckenridge, Colo., where Michael Malcolm’s younger son was charged in the overdose death of his older brother, with whom he shared drugs purchased on the internet. The cost of prosecution and incarceration, Mr. Malcolm said, would have been better spent on addiction treatment that the family could not afford. “It’s kind of like blaming the leaves on the tree, you know?” he said. “What about the roots?”