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Press Release

Four Plead Guilty to Healthcare Offenses, Including Doctor and Lab Owners

For Immediate Release
U.S. Attorney's Office, Northern District of Texas

Four defendants in separate, but related, cases pleaded guilty for their roles in a scheme to pay and receive kickbacks in relation to toxicology tests, announced U.S. Attorney for the Northern District of Texas Leigha Simonton.

Mark Rubin, 58, Renee Field, 44, Kelly Nelson, 52, and Carlos Hornedo, 61, were all charged via felony informations in December 2023. Mr. Rubin, on January 17th, and Mr. Hornedo, on January 10th, both pleaded guilty to one count of conspiracy to solicit and receive illegal kickbacks. On December 13th, Ms. Field and Ms. Nelson both pleaded guilty to one count of conspiracy to pay and receive health care kickbacks. The defendants each face a maximum penalty of not more than five years in federal prison, a $250,000 fine, and may be ordered to pay restitution.

According to the plea documents filed in the case, Ms. Fields was the owner and the Clinical Director at RK Clinical Solutions, LLC (“RK”). Ms. Nelson was the co-owner of RK. RK sought to financially incentivize medical providers to send tests to RK by providing them with illegal financial incentives that were disguised as legitimate business transactions.

Dr. Rubin, a pain management doctor, agreed to submit the majority of his toxicology orders to RK in exchange for kickbacks He also agreed to order a significant number of toxicology tests to justify the kickbacks. RK was paid by Medicare and other federal healthcare programs in excess of $481,000 and in exchange, Dr. Rubin received over $330,000 in kickbacks. The kickbacks consisted of medical advisor agreement, in which Dr. Rubin would be paid for theoretical advisory services. Dr. Rubin did not perform services sufficient to justify his compensation, was not paid on an hourly rate, and the agreements were used as a way to funnel kickbacks to Dr. Rubin.

In a similar fashion, Dr. Hornedo, a medical doctor, agreed to order certain toxicology tests for patients he saw and ordered the test to be performed by Unified Laboratory Services, LLC (“Unified”) and Spectrum Diagnostic Laboratory, LLC (“Spectrum”). Dr. Hornedo agreed to submit a substantial number of his toxicology orders to Unified and Spectrum in exchange for kickbacks. He submitted orders that resulted in billings by Unified and Spectrum in excess of $4,100,000 to federal health care programs. In exchange, Dr. Hornedo received approximately $412,000 in kickbacks, $45,000 in lease payments, $109,000 in medical advisor payments and ownership shares in Reliable Labs, LLC.

The Federal Bureau of Investigation, the Defense Criminal Investigative Service (DCIS), and the Veterans Affairs’ Office of Inspector General is investigating the case, along with the assistance of the U.S. Department of Health and Human Services’ Office of Investigations. Assistant U.S. Attorneys P.J. Meitl and Nancy Larson are prosecuting. 


Erin Dooley

Public Affairs Officer


Updated January 31, 2024

Health Care Fraud