The essential element of aggravated indecent assault under s 66(1)(a)(i) of the Criminal Law (Codification & Reform) Act is penetration of any part of the female body. Where evidence shows only kissing without proof of penetration, and the trial court fails to canvass the nature of the kiss to establish penetration, the State has not proven the offence beyond reasonable doubt. In such circumstances, where the evidence establishes physical contact of an indecent nature without penetration, the appropriate conviction is indecent assault under s 67(1)(a)(i), which is a permissible verdict under s 275 read with the fourth schedule to the Criminal Law Code. A reviewing court may exercise its powers under s 29(2)(b) of the High Court Act to alter the conviction and substitute an appropriate sentence.