A travelling medical technician who stole painkillers and infected dozens of patients with hepatitis C through tainted syringes was jailed for 39 years.
"I don't blame the families for hating me," David Kwiatkowski said after hearing around 20 statements from people he infected and their relatives. "I hate myself."
Kwiatkowski, 34, was a cardiac technologist in 18 hospitals in seven states before being employed at New Hampshire's Exeter Hospital in 2011. He had moved from job to job despite being sacked at least four times over allegations of drug use and theft.
Since his arrest last year, 46 people have been diagnosed with the same strain of hepatitis C he carries.
US attorney John Kacavas said the sentence "ensures that this serial infector no longer is in a position to do harm to innocent and vulnerable people".
Kwiatkowski admitted stealing painkillers and replacing them with saline-filled syringes tainted with his blood. He pleaded guilty in August to 16 federal drug charges.
Before he was sentenced, Kwiatkowski stood and faced his victims, saying he was very sorry and that his crimes were caused by an addiction to painkillers and alcohol. He told investigators he had been stealing drugs since at least 2003 and swapping syringes since at least 2008.
"There's no excuse for what I've done," he said. "I know the pain and suffering I have caused."
The victims spoke angrily and tearfully of the pain that Kwiatkowski had inflicted by giving them hepatitis C, a blood-borne virus that can cause liver disease and chronic health problems. Authorities say the disease played a role in one woman's death.
"You may only be facing drug charges, but make no mistake, you are a serial killer," said Kathleen Murray of Elmira, New York, whose mother was infected in Baltimore and was too ill to travel to Concord, New Hampshire, for the sentencing.
Linda Ficken, 71, said she was haunted by the memory of Kwiatkowski standing at her hospital bedside in Kansas for more than an hour applying pressure to the catheter's entry site in her leg to control bleeding.
"On one hand, you were saving my life, and on the other hand, your acts are a death sentence for me," Ms Ficken, of Andover, Kansas, told him. "Do I thank you for what you did to help me? Do I despise you for what your actions did and will continue to do for the rest of my life? Or do I simply just feel sorry for you being the pathetic individual you are?"
Prosecutors said Kwiatkowski deserved 40 years for creating a "national public health crisis", putting a significant number of people at risk and caused substantial physical and emotional harm to a large number of victims.
Assistant US attorney John Farley called Kwiatkowski's actions "exceedingly callous" and "unbelievably cruel" and noted that he could have stolen painkillers without exposing his patients to hepatitis C.
Defence lawyers argued that a 30-year sentence would better balance the seriousness of the crimes against Kwiatkowski's mental and emotional problems and his addiction to drugs and alcohol, which they said clouded his judgment.
Two of the 16 charges stem from the case of Eleanor Murphy, a Kansas woman who has since died. Authorities say hepatitis C played a contributing role.
"You ultimately gave my mother a death sentence," her son, Ronnie Murphy, told Kwiatkowski.