A Level 2 sex offender who was convicted of raping 7 and 8-year-old girls has been sentenced to prison after the feds busted him for child pornography.

Billerica man Eric Johnson, 51, was sentenced to 10 years in federal prison on Thursday, according to the Massachusetts U.S. Attorney’s Office.

The Level 2 sex offender — who was convicted in 1992 for aggravated felonious sexual assault of a child under 13 for raping two girls in New Hampshire — was caught possessing more than 5,000 files of child sexual abuse material.

Children’s clothing, mutilated dolls and diapers were also found at his home.

“Mr. Johnson is an extremely dangerous individual who has repeatedly demonstrated his predatory interest in children,” said Acting U.S. Attorney Joshua Levy. “He belongs in prison for a long time.

“The victims of child pornography are not abstractions or objects – they are real kids who experienced sexual exploitation in order for these pictures or images to be distributed and possessed,” Levy added. “Although today’s sentence cannot erase the ongoing pain endured by the victims from their traumatic abuse, the message about the severe consequences of possessing child pornography should be crystal clear.”

In early 2022, Johnson was identified as a user of a peer-to-peer internet network downloading child sexual abuse material. Police searches of his home resulted in the recovery of 25 electronic devices, including a laptop, hard drives and other electronic devices.

Multiple hard drives were found hidden next to Johnson’s bed — as well as hidden inside Johnson’s basement ceiling, shelves, cabinets, and in an ammunition can located in a crawl space at the residence. The laptop at the time was running a program to delete files from a hard drive, and was about 56% complete before being disabled by a forensic examiner.

Police also found two children’s backpacks from under his bed that contained various children’s clothing, including: bathing suits and a nightgown; a bag of children’s costumes; children’s diapers; and at least three child-sized dolls. What appeared to be bodily fluids were found in at least two of the dolls, police said.

A forensic exam revealed more than 5,000 files depicting child pornography on seven of the devices, including images and video files depicting the sexual abuse and rape of minor victims as young as infants and toddlers.

Many other disturbing items were also located on the devices, including images and videos of bestiality, photos of women’s deceased bodies, as well as videos of Johnson engaging in sexual acts with dolls.

“This lifetime sex offender admitted to amassing thousands of images of babies, toddlers, and children suffering horrific sexual abuse, and today’s sentence reflects the severity and depravity of his crime,” said Jodi Cohen, special agent in charge of the FBI Boston Division.

“Those photos and videos represent unimaginable pain forced upon utterly vulnerable victims, some too young to walk or talk,” Cohen added. “It’s cases like this that drive the FBI and our partners, as we work to protect the children in our communities from predators like Eric Johnson.”

In addition to the 10 years in prison, Johnson was sentenced to five years of supervised release. Johnson was ordered to pay restitution and forfeiture in the amount of $38,000.

Johnson pleaded guilty to one count of possession of child pornography earlier this year. He has remained in federal custody since his arrest in February 2022.