An Arlington man has been sentenced in federal court in Boston for possession of child pornography.

Mason Lister, 27, was sentenced on July 28 by U.S. District Court Judge Allison D. Burroughs to 10 years in prison and five years of supervised release. On Dec. 16, 2021, Lister pleaded guilty to one count of possession of child pornography.

“My office has a responsibility to ensure the safety of our communities, especially that of our most vulnerable – children," U.S. Attorney Rachael S. Rollins said in a news release. "Mr. Lister is a recidivist offender, a three-time convicted felon, who will now thankfully remain out of our communities and away from our children for the next decade.

"With the full support of our state, local and tribal law enforcement partners, we remain committed to protecting our children and prosecuting those who seek to exploit them.”

Repeat offender

Matthew Millhollin, special agent in charge for homeland security investigations in New England, added in the release: “Lister is a repeat offender, having already been convicted twice for child pornography-related offenses. This 10-year sentence will deny Lister the opportunity to further victimize innocent children through his online conduct and demonstrates our resolve to hold repeat offenders responsible to the full extent of the law.”

In their announcement, Rollins and Millhollin said they were assisted in the investigation by the Arlington Police Department. Assistant U.S. Attorney David G. Tobin of Rollins’s Major Crimes Unit prosecuted the case.

This case arose from a notice to law enforcement that a social-media account belonging to Lister had been used to distribute child pornography.

On July 23, 2020, a search of Lister’s residence resulted in the seizure of a tablet device containing at least 85 files of child pornography. The mix of files were both images and videos and depicted victims as young as toddler age. Lister was subsequently arrested on Aug. 14, 2020, and has remained in federal custody since. Lister has two previous state convictions for child-pornography offenses.

2017 case

In 2017, Lister was arrested in July on child-pornography charges for the second time in two years and that October was indicted by a grand jury in Woburn.

The Lancaster Road resident was charged with possessing child pornography (two counts), subsequent offense and distribution of child pornography.

That July, Arlington police arrested Lister, a former Newton day-care worker who did not work with children. He had been arrested on similar charges the previous year.

Police noted he was "known to police." In 2016, Patch reported police alleged that Lister had traded obscene images of children using social-media platforms. He formerly worked at Family ACCESS day care on Waltham Street in Newton.

In July 2017, members of the Arlington Police Criminal Investigation Bureau working with the FBI Child Exploitation Task Force served a search warrant at his home and found a cell phone with several images of what they described as child pornography. Police said Lister allegedly used the social-networking website Skout.com to trade explicit images of children.

"The Arlington Police Department takes an extremely strong stance on child exploitation, and we dedicate resources to not only finding missing and exploited children, but also rooting out those who create, distribute or possess depictions of child sexual abuse," then-Chief Fred Ryan said at the time. "We will continue to pursue these felons in an aggressive manner."

Project Safe Childhood

The case was brought as part of Project Safe Childhood. In 2006, the Department of Justice created Project Safe Childhood, a nationwide initiative designed to protect children from exploitation and abuse. Led by the U.S. Attorneys’ Offices and the DOJ’s Child Exploitation and Obscenity Section, Project Safe Childhood marshals federal, state and local resources to locate, apprehend and prosecute individuals who exploit children, as well as identify and rescue victims.

For more information about Project Safe Childhood, click here >> 

Oct. 17, 2017: Arlington man indicted in 2nd child-pornography case

This news summary was published Wednesday, Aug. 3, 2022, based on information from the U.S. Attorney's Office in Boston and from YourArlington files.