concurring. I agree that a new trial is necessary because of the failure of the trial court to exclude the three convictions for possession of narcotics (1966, 1970 and 1978), but the use of the 1973 conviction for sale of heroin was admissible to show intent to sell, an essential element of the crime charged, under State v. Amaral, 179 Conn. 239, 244-45, 425 A.2d 1293 (1979). Since that conviction was of substantial significance upon a vital issue in the case upon which there was very little additional evidence, its probative value would clearly outweigh its prejudicial effect. State v. Ibraimov, 187 Conn. 348, 352, 446 A.2d 382 (1982); State v. Holliday, 159 Conn. 169, 173, 268 A.2d 368 (1970). The fact that the state did not offer the evidence for that purpose is immaterial, because we frequently uphold trial court rulings where the evidence is admissible on a basis different from that relied upon in the trial court. “Where the trial court reaches a correct decision but on mistaken grounds, this court has repeatedly sustained the trial court’s action if proper grounds exist to support it.” Favorite v. Miller, 176 Conn. 310, 317, 407 A.2d 974 (1978); Saporiti v. Austin A. Chambers Co., 134 Conn. 476, 478, 58 A.2d 387 (1948); Witek v. Southbury, 132 Conn. 104, 110, 42 A.2d 843 (1945). The fact that the 1973 conviction was introduced to impeach the defendant’s credibility created no greater prejudice than would have ensued if it had been admitted for the purpose of showing intent to sell.
At the retrial of this case, which we now order, the state presumably will offer the 1973 conviction as evidence of intent to sell in order to sustain its burden of proving that element of the crime charged. Although the majority opinion maintains that this issue was not “seriously contested,” there is nothing in the record to support such an assumption. That the defendant limited his testimony to a denial of possession did not relieve the state of its burden of proving the requisite *18mental element beyond a reasonable doubt. The majority opinion1 leaves unresolved the admissibility of the 1973 conviction for sale of heroin as evidence of the defendant’s intent to sell in this case. Since the issue is likely to arise at the new trial, our function as an appellate court demands that we determine the question at this time rather than create the possibility of another appeal and a third trial.
See footnote 7, supra.