Kristen Parker lurks in the OR, watching over her shoulder as the anesthesiologist leaves the room. The 26-year-old surgical tech is alone. Finally. It's been several days between scores, too many hours since she's masked the pain of a failed relationship with the father of her young son. In a quick, practiced stroke, she swipes a fentanyl syringe from the anesthesia cart, replacing it with a needle full of sterile saline solution that she had hidden in her scrub pocket. No one will ever know, she convinces herself, already looking forward to her lunch break, her next opportunity for a quick hit of sweet relief.

Months later she cries in a police interview room, detailing how she routinely diverted fentanyl to feed the demons that will now haunt the 15 patients (and counting) she infected with hepatitis C. Choking back tears, she issues a simple warning to the naive. "Be more aware of what you leave laying around, as messed up as that may sound. If you leave meds lying around, someone, anyone, can take them."

"I knew my limit"
On Oct. 21, 2008, Ms. Parker was hired as a surgical tech at Rose Medical Center in Denver, Colo. She thought it was a new beginning, an escape from Westchester, N.Y., where her ex lived and where she had been fired from Northern Westchester Hospital for what she termed "attendance issues." Her tech duties at Rose allowed her access to sterile saline solution, unused syringes and medication labels. It was too great a temptation for an addict who packed a dependence on painkillers in the baggage she carried to Denver.

The routine she used to divert fentanyl was simple and effective. She'd grab a sterile saline solution bottle out of a storage cabinet, pull 5cc of the solution into a new syringe, apply a fentanyl label and keep it in her scrub pocket, hoping for a small window of time alone in an OR, the mere seconds she needed to grab a fentanyl syringe and leave the saline needle in its place.

Diverting opportunities didn't present themselves every shift or every case. "A lot of times (the fentanyl) wouldn't be available," said Ms. Parker during a police interrogation video. "There were only certain times someone would leave it laying around. I couldn't get into the Pyxis machine or didn't have access if the doctor had (the syringes) on his body."

After a successful switch, Ms. Parker would keep the fentanyl syringe in her scrub pocket until she could sneak to a private restroom to inject carefully measured doses into her arm in the few minutes before a case began, during breaks or over her lunch hour.

The small doses — between 2mL and 5mL — let her ration the painkiller, saving it for when she needed it most: before long cases or after lifting heavy instrument trays, for example. On occasion, she even took fentanyl syringes out of the hospital, bringing them back empty after satisfying her cravings at home.

Despite working high, she didn't think her colleagues ever noticed that she was impaired. "I knew my limit and didn't want to make it obvious to everybody that I was using," she told police. "I knew how much it would take for someone to catch on or to tell that I wasn't able to do my job."

Ms. Parker's habit ultimately, inevitably, put Rose's patients at risk. After emptying syringes of fentanyl into her arm, she'd occasionally carry several used needles in her pocket. It was a recipe for disaster as she prepared for her next syringe switch. "If I had 2 syringes in my pocket, I'd grab 1 to pull up the saline. There was no knowing if it was clean or dirty."

She claimed to have diverted fentanyl 15 to 20 times between January and April 2009. During that time, contaminated needles filled with saline ended up on anesthesia carts, putting thousands of patients at risk for HCV infection.

The noose tightens
Ms. Parker's drug diverting scheme began to unravel on March 23, 2009, the day a fentanyl syringe stuck a co-worker in the arm. "I had (stolen a syringe) earlier that morning and the cap had fallen off the needle," she explained to police. "We were talking in the hallway, and as someone pushed a stretcher by, I leaned forward. The needle was sticking out of my pocket."

After the incident, Ms. Parker was placed on administrative leave pending the results of a drug screening urinalysis. It came back negative, so 7 days after 1 of her stolen syringes stuck a co-worker, Ms. Parker returned to the scene of the crime. Less than 2 weeks later, a colleague noticed her alone in an OR. "I had just gotten a new car the day before, and went into the room to tell (a friend) about it," said Ms. Parker. "I saw that the room was (empty), and that's when I tried to make the switch."

Caught in the act, Ms. Parker told her co-worker that she was setting up the room, even though she wasn't assigned to the scheduled case. She was again given a drug test and placed on administrative leave. On April 20, 2009, Ms. Parker submitted a resignation letter, a clear sign she knew that her drug test would show traces of fentanyl. A day later, she was proven correct. Rose refused the resignation, terminated her employment and reported the positive drug test to the Colorado Department of Public Health and Environment.

The CDPHE investigated the incident throughout June 2009. It interviewed Ms. Parker 3 times and tested her for HCV and HIV. During those interviews, Ms. Parker admitted to diverting fentanyl at her new place of employment, Audubon Surgery Center in Colorado Springs, where she had begun working as a per-diem tech in early May. Audubon's administrator, Brent Ashby, says 2 of the facility's nurses interviewed Ms. Parker; they checked her references and subjected her to a urinalysis test to check for recreational drug use. They claim a review of Ms. Parker's references and her drug test results did not reveal anything suspicious, and say they hired her because she was a skilled and knowledgeable surgical tech.

"Her behavior was entirely appropriate and professional," says Mr. Ashby. "There was nothing going on here that aroused our suspicions."

Audubon didn't know that they had just hired a drug addict who was in the middle of a slowly tightening dragnet. On June 25, the CDPHE notified Ms. Parker to "cease and desist any employment that requires contact with patients or pharmaceuticals," citing 9 positive cases of HCV discovered at Rose. On June 29, the CDPHE confirmed Ms. Parker had tested positive for HCV. A day later, she turned herself into authorities, admitted to diverting fentanyl, but claimed she wasn't aware that she carried the infectious disease.

When did she know?
Ms. Parker was indicted by a federal grand jury in Denver on July 23 and charged with 21 counts of tampering with a consumer product and 21 counts of obtaining a controlled substance by deceit or attempt. She was held without bail. All 42 counts are related to her actions at Rose, although she may face additional charges as patient testing and investigations at Audubon progress. As of July 24, the CDPHE linked Ms. Parker to 14 cases of HCV at Rose and 1 case at Audubon, although Mr. Ashby says he's waiting on more conclusive testing before he agrees with the CDPHE's findings.

Ms. Parker faces up to 10 years in federal prison and a fine of up to $250,000 for each count of tampering with a consumer product, according to the United States Attorney for the District of Colorado. If patients suffer serious bodily injury, she could face up to 20 years in federal prison. She faces up to 4 years in prison and up to $250,000 in fines for each count of obtaining a controlled substance by deceit.

The criminal charges in this case hinge on a simple question: When did Ms. Parker know she had HCV? The true answer appears to be more complicated.

On July 15, the New York State Department of Health reported that Northern Westchester Hospital notified around 2,800 patients that Ms. Parker worked at the hospital from Oct. 8, 2007, to Feb. 28, 2008, putting them at possible risk for HCV exposure. Ms. Parker also worked at Christus St. John Hospital in Houston, Texas, although the hospital has not reported cases of HCV infection. It's not known if she diverted fentanyl while working at those facilities.

On Oct. 9, 2008, Ms. Parker submitted to a blood test before her hiring at Rose. She says she was told on her first day that the test results indicated HCV numbers that "were higher than normal" and she "might want to get them checked out."

She never did, blaming her negligence on the absence of HCV symptoms, her lack of medical insurance, her focus on her new job and an apparent lack of urgency from the Rose administration. "If they had said, ???This is serious, you need to go get this checked out,' or ???We can't do anything until we know for sure,' then it would have been a lot more pertinent for me to find out what was going on," she told police during her taped interrogation.

"When her results returned positive, she was counseled for 20 minutes on Oct. 20 — before her employee orientation — by an employee health nurse," says a Rose spokeswoman. "The nurse urged her to see her personal physician, and also offered to make an appointment for Ms. Parker at Rose's clinic, where she could receive care for a reduced cost."

The spokeswoman says the hospital is "absolutely certain" that the employee health nurse counseled Ms. Parker that she was positive for HCV, notified her of its implications and urged her to see a physician.

But Ms. Parker claims she wasn't sure she had HCV until June 2009, when the CDPHE called to let her know she had tested positive. She told police she's almost certain she contracted the disease when she shared a needle with a heroin addict while crashing with friends in New Jersey before moving to Colorado.

Until the CDPHE confirmed her diagnosis, Ms. Parker continued to divert fentanyl, ignoring not only the likelihood that she carried HCV, but also the dangers of administering saline solution instead of a painkiller to patients. Didn't she consider that she was putting patients in harm's way? "No I didn't, because the anesthesiologist monitors patients during the entire case," she told police. "I always figured that if patients were in pain, they'd give them something to make the pain go away."

But what about the mental and physical anguish of the patients who are facing a lifetime struggle with HCV, and the reputations of the nurses and techs at Rose and Audubon? Who will make their pain disappear?

"I had a problem and I guess my pride, my career, my family got in the way of me getting the help I needed," Ms. Parker tearfully told police. "I didn't know that this was going to happen. I mean, to the extent that people would be sick for the rest of their lives because of me. Now I have to live with what I did for the rest of my life, and so does everyone else."