A former Texas pediatric cancer doctor was sentenced to seven years in federal prison after being convicted on three child pornography charges.

U.S. District Judge George C. Hanks Jr. ordered ex-pediatric oncologist Dennis Patrick Meehan Hughes to serve seven years in federal prison for accessing, receiving, and possessing child pornography, announced U.S. Attorney Kenneth Magidson. In handing down Hughes’ sentence, the court noted the horrific nature of his crimes in that they facilitated the sexual abuse of children.

Hughes, 50, was emotional at the sentencing hearing Monday where he apologized and expressed remorse for his actions to a courtroom that included friends and colleagues, according to the Houston Chronicle.

His prison term for the three convictions will run concurrently. After completing his time, Hughes must register as a sex offender and serve 10 years of supervised release. He will have to comply with undisclosed restrictions that inhibit his access to children and to the internet. The court also imposed a $5,000 special assessment under the Justice for Victims Trafficking Act of 2015.

For over a decade, Hughes was a pediatric cancer specialist at top ranked University of Texas MD Anderson Cancer Center. He resigned following his June 2015 arrest. The Texas Medical Board suspended his license, KPRC reported.

Hughes was one of more than 135 suspects nationwide taken into custody in a federal sting called Operation Pacifier, which targeted users of a “Dark Web” child pornographic site that featured lewd images of prepubescent children.

In early February 2015, federal authorities arrested the primary site administrator. Then, investigators identified 1,000 U.S.-based IP addresses; one led them to Hughes. In June, law enforcement obtained a warrant and searched his home, seizing his computers and other digital equipment. According to the U.S. Department of Justice (DOJ), agents found 329 obscene videos and 2,693 lubricious images of young girls on computers at Hughes’ home and on a work device.

At the time, Hughes was released on bond. The judge ordered him to wear a GPS monitor, not to access the internet, surrender his passport, and have no unsupervised contact with minors, except his own underage children. He also barred Hughes from attending places where children congregate like schools and parks. Then, in March 2016, Hughes pleaded guilty to the three child porn charges.

At the sentencing hearing Monday, Hughes’ attorney Neal Davis said: “It’s obviously been a real tragedy; it’s a very sad case.” He told the Houston newspaper: “We’re grateful that the judge recognized that (he) has made great strides in atoning for what happened. He has great promise to still do great things as a research scientist.”

The court allowed Hughes to remain free on bond and voluntarily surrender to a U.S. Bureau of Prisons facility to be determined in the near future.

Assistant U.S. Attorney Sherri Zack prosecuted the case in the Southern District of Texas. It was conducted as part of Project Safe Childhood, a nationwide initiative launched in May 2006 by the DOJ, to combat the growing epidemic of child sexual exploitation and abuse. Led by United States Attorneys’ Offices and the Criminal Division’s Child Exploitation and Obscenity Section, Project Safe Childhood marshals federal, state and local resources to locate, apprehend and prosecute individuals who sexually exploit children, and to identify and rescue victims.

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