The Supreme Court said Monday it will consider the extent of the federal government’s power to detain for deportation immigrants who have served time for criminal acts.

There is a split in the lower courts on whether federal officials must act immediately after the person is released from criminal custody to detain them indefinitely as they await deportation proceedings. The case will be heard in the term that begins in October.

The U.S. Court of Appeals for the 9th Circuit said that unless the arrest is prompt, the detainee should receive a hearing to determine whether they may be freed awaiting the outcome of the deportation proceedings. Immigrants would have to convince an immigration judge that they posed no danger to others and were not a flight risk.

Other lower courts have agreed with the government’s reading that detention is mandatory no matter when the noncitizen is picked up.

The government argues that the 9th Circuit’s approach will lead to a “gap in custody” and hamper the federal government’s ability to remove deportable immigrants. The Trump administration said the efforts of “sanctuary cities” reluctant to cooperate with federal authorities escalate the difficulties.

The Obama administration took the same reading of the law, but the stakes are higher with President Trump’s vow to remove more noncitizens who have committed crimes that make them deportable.

The 9th Circuit case involved two people in unrelated cases.

Mony Preap was born in a refu­gee camp after his parents fled Cambodia, and he has lived legally in the United States since 1981. He was convicted in 2006 of marijuana possession, but was not picked up by federal authorities after he was sentenced to time served.

He served another criminal sentence for battery in 2013, a charge that is not a deportable offense. He was detained for months, but was released and no longer faces deportation.

Bassam Yusuf Khoury has been a lawful permanent resident of the United States since 1976. In 2011, he was released after serving a 30-day sentence for a drug charge. Nearly two years later, federal authorities picked him up for deportation and he was detained for more than six months before a judge said he could be released.

The issue concerns language in the federal law that authorizes the Department of Homeland Security to seize someone for deportation “when the alien is released” from criminal custody.

The federal government says it could mean any time after the release, not just immediately after the release.

Lawyers for the detainees say that under the government’s reading, that would impose mandatory deportation “on individuals who have been released months, years, or even more than a decade earlier, and who therefore have an actual record of living at liberty in the community without posing any flight risk or danger to others.”

The court decided a related case last month. On a 5-to-3 vote, the court said federal law did not require a bond hearing even after months or years of detention of those facing deportation.

The case to be heard is Nielsen v. Preap.

Death penalty case rejected

Also Monday, the court turned aside a lawsuit that had been intended as a challenge to the constitutionality of the death penalty in Arizona and elsewhere.

The court’s four liberals said the case raised important questions but was not the right vehicle for such a challenge.

The request came from Abel Daniel Hidalgo, convicted of a pair of 2001 killings. He had been hired to kill Michael Cordova for $1,000. But another man, Jose Rojas, was at Cordova’s auto repair shop, and Hidalgo killed him as well — “one paid and one complimentary,” the state said in its brief telling the court not to take the case. At the time of his arrest, Hidalgo was being held in connection with a double-murder committed in Idaho.

Hidalgo’s lawyer, Neal Kumar Katyal, said the Supreme Court’s precedents require states to structure their death-penalty statutes so that they apply capital punishment to the worst of the worst.

But Arizona’s is too broad, Katyal argued. It has so many aggravating circumstances that can lead to a death sentence that 99 percent of those convicted of first-degree murder in the state are eligible.

The Arizona Supreme Court upheld the state’s law, noting that death sentences are not sought in most first-degree murder cases, and that each of the individual factors did in fact narrow the application of capital punishment.

Justice Stephen G. Breyer, who in 2015 called for a new examination of whether the death penalty could be applied constitutionally, wrote that Hidalgo’s case raised important questions. But “the record as it has come to us is limited and largely unexamined by experts and the courts,” Breyer wrote.

Breyer was joined by justices Ruth Bader Ginsburg, Sonia Sotomayor and Elena Kagan. Only Ginsburg has joined Breyer’s call for a reexamination of the death penalty.

The case is Hidalgo v. Arizona.