Justice Libman was appointed to the Ontario Court of Justice in 1996. He serves as Chair, Rules Committee of the Ontario Court of Justice, and is an Associate Editor of the Motor Vehicle Reports.

Justice Libman is a recognized authority on the rules of court and on regulatory offences. He is the author of the seminal Canadian work on regulatory offences, Libman on Regulatory Offences in Canada, and of Criminal Trial Rules in Provincial Courts in Canada, Fully Annotated, 2020-2021 Edition. Both titles are available through Earlscourt Legal Press.

He has also authored publications on the Provincial Offences Act (Ontario) and the Contraventions Act (Canada).