Published: Apr 28, 2014 12:38 PM EDT
Updated: Apr 28, 2014 6:31 PM EDT

LEE COUNTY, Fla.- A North Fort Myers man has pleaded guilty to what investigators have described as a horrific case of child abuse, and one of the worst they've ever seen.

Alan Johnson was accused of molesting a 4-year-old girl and using her to create child porn back in 2012. Today, Johnson plead guilty to three counts of lewd and lascivious molestation. Investigators said they found hundreds of pictures of Johnson molesting the 4-year-old and posing with her, along with his girlfriend, Jennifer Sparks.

The child's mother was from Tampa, and allowed her to stay with the couple for six months. 

The pictures were found on the couple's cell-phone that was left behind at a Lee County Walmart.

"He recognizes the fact that he is in serious trouble. and that he's going to be in prison for a long time," said Johnson's attorney, James Ermacora.

Johnson's attorney said several factors lead to today's deal. In February, a judge denied the couple's motion to have the pictures found on their cell phone thrown out in court, making trial risky because Johnson faced a sexual capital battery charge, which carries a life sentence. That was taken off the table today.

"The plea agreement here gives him some light at the end of the tunnel, with respect to getting out. He'll be a fairly elderly gentleman when he does get out, but it still gives him some hope, whereas a life sentence in Florida, means a life sentence, you aren't getting out," said Ermacora.

Johnson was be officially sentenced on the 19th. As part of his deal, he will be sentenced to 30 years on the state charges.

Johnson took a plea deal in federal court earlier this year and will be sentenced this upcoming Monday. Those punishments will run at the same time.