Raul Johnson’s own words – and his conscience – got him convicted of attempted murder of a now 81-year-old former teacher and a potential prison sentence reaching 25 years.

Johnson, 20,  nearly three years after the stabbing, went to the Clarkstown police to finger the stabber. He convinced the police he knew who did it and the cops believed him and were enlisting him as a confidential informant.

Then, Johnson started changing the facts of the story.

First. the Haverstraw resident told them he saw the stabbing at ShopRite off Route 59 from across the road close to the Palisades Center, then moved himself closer and then closer to the scene.  Eventually, Johnson admitted punching the man and stabbing him, adding one of his friends also stabbed him.

His lawyer, Alan McGeorge, said without the confession, there wasn’t much evidence against Johnson.

Neither the victim or another witness could identify the attackers. The victim was grabbed from behind.

A jury at the Rockland Courthouse in New City convicted him Wednesday afternoon of second-degree attempted murder and first-degree assault.

Prosecutor Dominic Crispino said Johnson’s explanation for the stabbing was he was angry after a fight with his father. Apparently his conscience got the better of him and he went to the police, Crispino agreed.

But Johnson’s change of heart will not prevent Crispino from asking state Supreme Supreme Court Justice William Kelly for an extended prison sentence on Dec. 8. Johnson faces five to 25 years for second-degree attempted murder and first-degree assault. He was offered 10 years in prison before trial, so Crispino’s recommendation to Kelly is likely to top that offer.