What Makes This Death Penalty Case in Illinois Unusual

University of Illinois graduate student Yingying Zhang disappeared in June. The Chinese woman's body has not been found, but federal prosecutors believe that Brendt Christensen is responsible for her murder—and they announced Friday that, with Attorney General Jeff Sessions' blessing, they will pursue the death penalty in their case against him. The Chicago Tribune looks at just how rare a thing such a conviction and sentence would be. Illinois did away with the death penalty in 2011, and its use in federal court is far from commonplace. More on the case, the move, and the growing allegations against Christensen:

• The Tribune reports the last instance of the federal sentence being imposed in Illinois court was in 2005, when Dr. Ronald Mikos was found guilty of murdering a one-time patient who was cooperating in a Medicare fraud trial against him. The Supreme Court declined to hear his appeal in 2009, the AP reported at the time, but he still awaits execution.

• The AP reports that since 1927 there have been just 37 federal executions; all but three occurred prior to 1964, per the Death Penalty Information Center, and the most recent was in 2003. Among the best known names on the list: Ethel and Julius Rosenberg and Timothy McVeigh. The AP notes that of the 37, just one took place in Illinois, where Henry Seadlund was in 1938 hanged for kidnapping. There are currently 61 prisoners on federal death row, among them Boston Marathon bomber Dzhokhar Tsarnaev and Charleston church shooter Dylann Roof. To give perspective, as of July 1 there were 2,817 death row inmates overall in the US.
• The Washington Post explains that Sessions makes the final call regarding whether to seek a federal death sentence, and he's done that two times since taking office—but both since Dec. 19. Those two instances relate to the cases against Jarvis Wayne Madison, who's accused of kidnapping and killing his estranged wife, and Billy Arnold, an alleged gang member accused of murder.
• The Wall Street Journal spoke with a Justice Department official who said this marks the start of what will be an administration that more aggressively seeks the death penalty; the paper says the Obama administration sought a federal death sentence in "at least four dozen cases."

• As for the prosecution's motivation in seeking the death penalty against Christensen, they wrote in their motion that the 28-year-old "is likely to commit criminal acts of violence in the future that would constitute a continuing and serious threat to the lives and safety of others." The Tribune notes they brought forth a new allegation—that Christensen "choked and sexually assaulted" a victim referred to as "MD" in 2013, which is when he gained admission to U of I's physics grad program (he attained his degree). He also reportedly expressed a desire "to be known as a killer."
• The AP notes prosecutors also mentioned his alleged torture of Zhang before her murder as part of their reasoning for the sentence, though they didn't elaborate. Their five-page filing alleges "planning and premeditation" and notes "the victim was particularly vulnerable due to her small stature and limited ability to communicate in English."
• The News-Gazette has this statement from the lawyer for Zhang's family: "The tragedy of the brutal crime that has harmed their daughter demands the greatest, ultimate punishment. The family's foremost wish has always been to find Yingying and return her home. ... They express appreciation and respect for the process, including consideration of the family's wishes in arriving at the decision to seek the death penalty in this case."

Christensen is accused of making other dark comments and visiting kidnapping fetish sites. (More death penalty stories.)