Tina,

It would be best to consult with a local lawyer to find out what the consequences of refusing the polygraph would be.

If you fail the polygraph examination, then that fact might be used against you in considering whether you have violated the terms of your probation, depending on your state's laws.

There are techniques called countermeasures that you can use to reduce the risk of a false positive outcome. You'll find these described in The Lie Behind the Lie Detector (see Chapters 3 & 4).

Note, however, that you have posted enough information about yourself (that three people have accused you of slashing tires) that if your polygrapher were to read this post -- and some polygraphers do actively monitor this message board -- then he/she will know that you have visited this website and educated yourself about polygraphy.

Under the circumstances, your best option might be to adopt what we've termed the "complete honesty" approach by telling your polygrapher what you've learned about polygraphy. Again, I strongly suggest that you consult with a lawyer beforehand, as your liberty is at stake.