Following a bench trial, defendant was convicted of second-degree criminal sexual conduct, MCL 750.520c(l)(a); MSA 28.788(3)(l)(a), and was sentenced to three years’ probation, with seven days to be served in jail. She appeals as of right. We reverse.
Defendant’s assertions that she never waived the right to a jury trial on the record or signed a written waiver are not supported by the record. A review of the circuit court docket sheet indicates that defendant waived the right to a jury trial on the record in open court. Additionally, the circuit court file contains a written waiver form signed by defendant. No error is indicated. MCR 6.402(B).
Defendant’s conviction must be reversed because of the injection of polygraph test results into evidence. The mention of a polygraph examination was made by the prosecutor, who indicated that a detective’s report regarding the interview of defendant was titled polygraph examination. The prosecutor also admitted that he filed a copy of the polygraph examination report in the circuit court’s record. Although the prosecutor did not state that defendant failed the polygraph examination, defen*235dant’s failure was apparent from the officer’s testimony that he told defendant (during the polygraph examination) that he thought she was lying. Defendant’s failure of the polygraph examination was also apparent from the fact that the test was administered before she had been charged with second-degree criminal sexual conduct. Although the circuit court later found that it had not been influenced by this information, it did question the officer regarding the number of polygraph tests he had performed in the past — a question apparently designed to measure the officer’s expertise with the polygraph. This case presented a credibility contest. Under these circumstances, the prosecutor’s injection of the polygraph testing and results was unfairly prejudicial to defendant’s case because it provided supposedly scientific evidence of defendant’s lack of credibility. Reversal of defendant’s conviction is therefore required. People v Ray, 431 Mich 260; 430 NW2d 626 (1988); People v Kosters, 175 Mich App 748; 438 NW2d 651 (1989).
Although the circuit court’s findings were brief, they established that it was aware of the relevant issues in the case and correctly applied the law on all but the polygraph issue. Hence, the findings were sufficient under MCR 2.517(A). People v Wardlaw, 190 Mich App 318; 475 NW2d 387 (1991).
Finally, the circuit court did not err in allowing testimony that defendant had taken a bath with the five-year-old complainant and her younger sister. This could be considered prior inappropriate sexual behavior by defendant toward the complainant and was admissible. People v DerMartzex, 390 Mich 410; 213 NW2d 97 (1973).
Reversed and remanded for a new trial. We do not retain jurisdiction.
*236Fitzgerald, P.J., concurred.