2 charged with murdering witnesses, burying remains to thwart drug trafficking investigation following HSI San Diego, partner investigation

SAN DIEGO — A superseding indictment was partially unsealed in the Southern District of California March 5 charging alleged drug trafficker Benjamin Madrigal-Birrueta, 22, with murdering two people to prevent them from testifying in drug trafficking cases in federal court in San Diego. Homeland Security Investigations (HSI), the Drug Enforcement Administration, the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives are investigating this case with local law enforcement agencies.

The victims were identified as Cesar Armando Murillo, 44, and Maria Sofia Hernandez, 33, of Yakima, Washington. Court filings indicate Hernandez was six months pregnant when she was killed, and the superseding indictment includes a separate count charging Madrigal-Birrueta with the death of her in-utero child. Hernandez is survived by three children and Murillo is survived by two children.

“HSI continues to tirelessly investigate criminal organizations who traffic dangerous drugs across our border and into the interior of the United States. In this pursuit, we will ensure that anyone who is responsible for causing harm to a witness in one of our investigations is held accountable for these actions,” said HSI San Diego Special Agent in Charge Chad Plantz. “Fear or harm caused to those who report a crime or testify diminishes the public’s trust in the criminal justice system and erodes the foundation of the rule of law. HSI and its partners are committed to ensuring that anyone who tampers with witnesses or breaks the laws in place to protect them are brought to justice.”

According to court filings, the investigation originated with the seizure of drugs from late-model stolen vehicles using San Diego area ports of entry between August and October 2021. The indictment alleges that Madrigal-Birrueta was a leader in a criminal enterprise that committed a series of felony violations of federal drug laws, and that he is responsible for importing drugs.

By August 2022, the investigation led agents to a group of individuals operating out of Yakima. HSI special agents interviewed Murillo and Hernandez, and within days, the two were murdered and their bodies were buried in the high desert.

The superseding indictment also charges Ricardo Orizaba, 21, with being an accessory after the fact to murder.

Court filings describe how these charges follow an exhaustive, yearlong investigation that employed geophysicists, ground penetrating radar, aircraft, laser imaging, chemical testing of the soil, numerous cadaver dogs and other law enforcement techniques to search for the victims’ remains. HSI special agents successfully recovered the remains on September 13, 2023, aided by a Washington State Police Crime Scene Investigations team.

Court filings further indicate that, based on autopsy reports, both victims died of multiple gunshot wounds to the head.

During the investigation agents seized methamphetamine, cocaine, fentanyl, multiple firearms — including a machine gun — and body armor from Madrigal-Birrueta’s drug trafficking organization. In addition to the homicides, the superseding indictment charges Madrigal-Birrueta with possessing a machine gun in furtherance of a drug trafficking crime.

Federal courts in California and Washington have ordered that Madrigal-Birrueta and Orizaba be detained pending trial, and both are in custody.

“These executions were an assault on our justice system, designed to silence witnesses and instill fear,” said U.S. Attorney Tara McGrath. “The obligation to protect witnesses is paramount and the United States will fully prosecute intimidation and violence designed to interfere with the justice system.”

“The cartels and drug trafficking organizations have reached beyond our borders, bringing their criminality to every city and small town in our interior,” said Special Agent in Charge Robert Hammer, who oversees HSI operations in the Pacific Northwest. “The murder of witnesses is an affront to our rule of law, but HSI, along with our law enforcement partners, have the resources to uncover these horrible crimes and the dedication to dismantle the organizations harming our population, wherever they may be located.”

The charges and allegations contained in an indictment or complaint are merely accusations, and defendants are considered innocent unless and until proven guilty.

This case is being prosecuted by Assistant U.S. Attorneys Stephen H. Wong and Alicia P. Williams.

Agencies that contributed to this investigation include the Washington State Police, the California Highway Patrol, the Yakima Police Department, the Tulare County Sheriff’s Office, the Visalia Police Department, the Fresno Sheriff’s Office and the Fresno Police Department.

HSI is the principal investigative arm of the U.S. Department of Homeland Security (DHS), responsible for investigating transnational crime and threats, specifically those criminal organizations that exploit the global infrastructure through which international trade, travel and finance move. HSI’s workforce of more than 8,700 employees and consists of more than 6,000 special agents assigned to 237 cities throughout the United States, and 93 overseas locations in 56 countries. HSI’s international presence represents DHS’ largest investigative law enforcement presence abroad and one of the largest international footprints in U.S. law enforcement.