Thiersaint v. Commissioner of Correction

Summary

The court reversed habeas relief because the constitutional rule requiring counsel to advise noncitizen defendants about deportation consequences does not apply retroactively to the petitioner's already-final guilty plea. The court adopted the Teague framework for Connecticut habeas proceedings, while retaining independent authority to apply it, and concluded that the rule was new under that framework. The court also declined to review the petitioner's unpreserved due-process claim and concluded that his substance-abuse-defense claim had been waived.