A Pennsylvania mother and her boyfriend have been charged with homicide and related offenses after they killed her 14-year-old daughter in a “rape-murder fantasy,” prosecutors said Sunday.

Prosecutors said Sara Packer, 41, and Jacob Sullivan, 44, planned Grace Packer’s murder for more than a year, the Philadelphia Inquirer reports. The two killed Grace in July, and then hid her body in the attic of their rented home in Quakertown, Pa. for nearly four months and later dismembered it, officials said.

Before they killed her, Sullivan raped Grace while her mother watched, prosecutors said, according to the Inquirer.

“This was a sexual fantasy that was shared between Jacob Sullivan and Sara Packer, and Grace Packer was the object of that rape-murder fantasy,” Bucks County District Attorney Matthew D. Weintraub told the Inquirer.

On Sunday, Sullivan appeared before a judge on charges of homicide, rape, kidnapping, and related offenses. He was jailed without bail, the Inquirer reports. Shortly after, Sara Packer was arrested on charges of homicide, kidnapping, unlawful restraint, possessing instruments of crime, endangering the welfare of a child, and other related offenses. Her arraignment is pending.

Fox News reports that both offenders could face the death penalty.

Packer continued to collect Social Security payments for Grace after her death—pocketing about $3,600 in disability benefits for her daughter, according to Fox News.

After a double-suicide attempt, both Sullivan and Sara were hospitalized on Dec. 30. On Saturday, Sullivan reportedly confessed to hospital staff that he killed Grace.

Grace was bound, gagged and left to die in a closet in the attic that was supposedly “extremely hot,” prosecutors said. However, after later finding her still alive, Sullivan allegedly suffocated Grace to kill her. The two then packed her body in cat litter before later cutting it up, and then dumping her remains in a dam, according to the Inquirer. Her remains were found on Halloween 2016.

Get The Brief. Sign up to receive the top stories you need to know right now. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Contact us at letters@time.com.