<human>: Can you provide a brief overview of the text?

So about a year ago, my girlfriend at the time and I had a bad break-up. I initiated it because she couldn't trust me when I told her I was out with friends and she would text all my friends to confirm that I wasn't lying to her. Obviously after this happened several times after talked to her about it, I could not continue on with the relationship. We broke up about a week before prom and she, understandably, flipped out. 

Now, during our relationship she was aware that I may or may not have been selling marijuana. Fast forward to a few months ago, she and I were on friendly terms again because we had come to an understanding on why she was so untrusting(she was cheated on in a past relationship) while we dated. This is where it gets interesting, she tells me she was questioned by our school police officer some time after we broke up.

 According to her, a girl(she doesn't know who) had accused me of dealing and thats why the police were investigating her. Obviously I suspect that she's the one who accused me out of anger because no other girls I know would have the motivation. She maintains that she was only questioned by the police but didn't answer any questions. We have a good friendship currently and she acts like nothing is wrong. How should I approach this with her? I can't continue acting like nothing is wrong in the hopes she comes clean later on.
<bot>: Ex may have snitched on me after we broke up and isn't telling me the truth despite us being good friends now.