The order directs U.S. attorneys to promptly report to Justice Department headquarters when a sentence is a "downward departure" from sentencing guidelines and not part of a plea agreement in exchange for cooperation.
Prosecutors were told to make sure the government is prepared to appeal more of these sentences if such a decision is made by lawyers in Solicitor General Theodore Olsen's office.
The upshot is that more decisions to appeal will be made at "main Justice" in Washington rather than left to prosecutors in the field.
Justice Department spokesman Mark Corallo said the intent of Ashcroft's memo is to "get an accurate reporting of how the sentencing guidelines are being applied."
"It is an effort to make sure that someone who is convicted of a crime in California is treated no differently than a person who is convicted of the exact same crime in Massachusetts," Corallo said Thursday.
The memo, issued July 28, is part of a Justice Department effort to implement a law passed by Congress earlier this year intended to bring greater uniformity to prison sentences imposed by federal judges.
"The Department of Justice has a solemn obligation to ensure that laws concerning criminal sentencing are faithfully, fairly and consistently enforced," Ashcroft wrote in the memo, first reported Wednesday by The Wall Street Journal.
President Bush in April signed into law wide-ranging child protection legislation that, among other things, will establish a national "Amber Alert" communications network to respond to child abductions.
Tucked into that measure was a provision sponsored by Rep. Tom Feeney, R-Fla., intended to make it more difficult for federal judges to depart from federal sentencing guidelines and making it easier to appeal light sentences. Prosecutors have complained for years that judges have too much leeway in imposing sentences.
Feeney's amendment was opposed at the time by the American Bar Association and by Supreme Court Chief Justice William H. Rehnquist, who said in a letter to the Senate Judiciary Committee that it "would seriously impair the ability of courts to impose just and reasonable sentences."