Authorities raided the West Palm Beach Veterans Affairs Medical Center on Thursday, arresting more than a dozen employees and patients accused of selling drugs in the hospital's stairwells and parking lots. Nursing assistants, a pharmaceutical technician and a respiratory therapist were among those arrested on charges of trafficking in oxycodone or selling marijuana, according to Palm Beach County Sheriff's Office arrest reports. Local and federal authorities seized 6,000 oxycodone pills, $200,000 in cash and two cars. Thursday's multi-agency sweep was part of a seven-month investigation at the hospital -- Operation Tango Vax -- in which a confidential informant helped undercover agents buy pain pills, marijuana and other drugs from employees, patients and their relatives, the Palm Beach County State Attorney's Office said.Terri Guerra, a controlled-substance technician, faces up to 30 years in prison for conspiracy to traffic in oxycodone, according to an arrest report. U.S. Drug Enforcement Administration agents searched her Jupiter home in July and found about $100,000 in cash and 5,000 oxycodone pills in a safe.