ST CROIX, US Virgin Islands — A 36-year-old man from St Croix in the US Virgin Islands has been sentenced to five years in prison after authorities intercepted a package containing 800 fentanyl pills hidden inside a book.

Mario Felix was sentenced on September 1, 2026, by US District Judge Mark A. Kearney to 60 months in prison for causing attempted possession with intent to distribute fentanyl.

He was also sentenced to five years of supervised release and ordered to pay a $100 special assessment. 

Felix will receive credit for time already spent in detention.

According to US court documents, the package was randomly selected for inspection during an inbound examination of mail handled by the United States Postal Service (USPS) on December 31, 2022.

When the box was opened, officers found a book containing several plastic bags filled with 800 blue pills. The pills tested positive for fentanyl, a powerful synthetic opioid.

A Drug Enforcement Administration laboratory analysis later confirmed that the pills contained 88.67 grams of fentanyl.

The package was seized and sent to the USPS Forensic Laboratory Services for fingerprint analysis. Investigators found Felix’s fingerprints on the plastic bag containing the book and fentanyl pills.

The investigation also uncovered text messages between Felix and another individual that prosecutors said showed his involvement in sending the package.

On December 12, 2022, Felix asked the individual for their mailing address and last name. When the person asked what he was sending, Felix sent a picture of the book containing the fentanyl pills and said there was something inside it.

Felix told the individual he would pay them $800 after they received the package.

On December 17, he told the person that he did not have anyone to mail the box for him.

Ten days later, Felix said the package had been mailed but told the individual he could only pay $700 because he had to pay someone else to deal with the package.

He subsequently sent a picture of the postal receipt, including the package’s tracking number.

On December 30, Felix told the individual they could check the post office for the package. The person went to the post office but did not receive it after waiting.

The following day, the individual told Felix they were still waiting for a call and that the post office would close at noon. 

They were later told the package had not yet been found.

On January 2, 2023, the individual told Felix they had tried calling the post office but received no answer.

The investigation was conducted by Homeland Security Investigations and US Customs and Border Protection.