Since leaving her award-winning role as nurse Carole Hathaway on “ER” in 2000, Julianna Margulies hasn’t quite found as memorable a role on TV. Well, at least until now.

Margulies has found a good one in Elizabeth Canterbury, a defense attorney willing to bend the rules in pursuit of justice in “Canterbury’s Law,” which debuts at 8 tonight on Fox.

Canterbury is a mess. A personal tragedy has her marriage to Matt (Aidan Quinn) on the rocks. The facts that she drinks too much and is having an affair don’t help.

Her courtroom tactics are often successful, but how she gets there has her in trouble with the district attorney’s office, and her practice is soon at risk.

Working under her is former prosecutor Russell (Ben Shenkman), who often fills the role of her conscience, Chester (Keith Robinson), a congressman’s son who has turned his back on his father’s politics; and headstrong Molly (Trieste Kelly Dunn), who’s regularly in conflict with Canterbury. Yet these three come together to form a support staff for her.

When you take into account that Denis Leary (“Rescue Me”) is one of the executive producers, it becomes clear the direction that “Canterbury’s Law” will take: a successful professional whose demons threaten to bring her down.

Margulies has found a complex character in Canterbury. But in this most odd of TV seasons, late-arriving “Canterbury’s Law” could well be thrown out of court before viewers get enough evidence to render their verdict.