Villines

This is a revocation of probation proceeding. Appellant seeks reversal because of “fundamental unfairness,” grounded upon violation of due process, because the revocation was ordered at a second proceeding after the first proceeding had been dismissed due to the absence of a necessary prosecution witness. Appellant also urges that the court abused its discretion in permitting the toxicologist to testify as an expert, and, lastly, that the finding of violation of probation was not supported by clear and convincing evidence. We will reject appellant’s contentions and affirm the judgment.

Facts

On July 11, 1985, when appellant was placed on probation, he signed a paper advising him of the terms of probation. One of the conditions of probation was that appellant “[s]ubmit to drug use detection test as directed by a probation officer or any peace officer.”

On February 11, 1986, Probation Officer Steven Williams went to appellant’s residence to check whether appellant was staying clear of drugs. Because appellant was not home, Williams left instructions telling appellant to give a urine sample at juvenile hall that evening.

Sometime later, on that same date, or early the…