Washington ? The Supreme Court’s newest justice, Samuel A. Alito Jr., has yet to write a signed opinion – majority, concurring or dissenting. His vote has been recorded in only two cases so far.

But it won’t be long before Alito makes his mark. There are three cases on the court’s docket in which the 56-year-old junior justice will probably have the deciding vote.

These are the three cases the court has set down for reargument since Sandra Day O’Connor left the court and Alito took her place on Jan. 31.

Although the court did not announce why it decided to hold a second hour of oral argument on the cases, the likeliest reason, based on the experience of previous transitions on the court, is that in each instance O’Connor’s departure left the court divided 4 to 4.

If so, it will be up to Alito to break the tie, once he has had a chance to catch up on the briefs and hear the lawyers on both sides.

The three cases are Garcetti v. Ceballos, argued on Oct. 12 and reargued March 21; Kansas v. Marsh, argued on Dec. 7 and reargued last Tuesday; and Hudson v. Michigan, argued on Jan. 9 and to be reargued on May 18.

Alito is a former U.S. attorney, and, as it happens, all three cases come out of the criminal-law milieu.

Garcetti v. Ceballos involves a lawsuit by a former Los Angeles County prosecutor who said that his bosses retaliated against him because he wrote an internal memo charging a police officer with lying to get a search warrant in a murder case.

Richard Ceballos said the retaliation violated his constitutional right to free speech because his memo was about a matter of public concern. But the defendants, including former Los Angeles district attorney Gil Garcetti, argued that disputes over policy between public employees and their supervisors should not become potential First Amendment lawsuits.

Kansas v. Marsh is about Kansas’ death penalty law, enacted in 1994, which requires a death sentence in cases in which the jury finds that there is an exact balance between the factors favoring capital punishment and those weighing against death. Convicted murderer Michael Lee Marsh II said the rule saddled him with the burden of proving he should not be executed, which, he said, is unconstitutional.

Hudson v. Michigan involves the “knock and announce” rule for police raids. The Supreme Court has prohibited officers from simply barging in to execute a search warrant; instead, they must identify themselves and give the occupants a reasonable time to respond, except in emergencies. Otherwise, they cannot use the evidence at trial.

Booker Hudson said his rights were violated because officers did not knock and waited only three to five seconds before entering his house. Michigan conceded that was wrong, but said the evidence – drugs and a gun – should still be admissible because it would have been found even if the officers had waited longer.

Only two other cases from the court’s pre-Alito days, House v. Bell and Whitman v. Department of Transportation, remain undecided. The former involves a Tennessee death-row inmate’s claim of innocence; the latter is about grievance procedures for federal employees.

In oral arguments so far, Alito has generally been in a listening mode, limiting himself to a few terse questions.