A former U.S. Marine was convicted Tuesday of killing a fellow service member in what prosecutors described as a random, sexually motivated attack at Joint Base Myer-Henderson Hall, and jurors must soon decide whether he should be executed.

After deliberating for several hours over two days, jurors convicted Jorge Torrez, 25, of first-degree murder in the slaying of 20-year-old Amanda Jean Snell, who was found stuffed in a locker in her room in July 2009. Prosecutors said that Torrez, who lived doors away from Snell at the military base in Arlington County, crept into the woman’s room as she slept and strangled her with a laptop cord.

Torrez showed no reaction as the verdict was read in federal district court in Alexandria, although he gazed toward the jurors as each confirmed his or her decision aloud. Prosecutors have asked that Torrez face capital punishment for the crime, and later this month, the same jurors will decide whether he deserves to die.

Torrez’s crime is certainly heinous enough — and his victim sympathetic enough — to make the death penalty a possibility.

Snell, who grew up in Twentynine Palms, Calif., and Las Vegas, was known among family members for her outgoing nature and “infectious personality,” said Denise Alexander, her aunt. Alexander said that Snell volunteered helping autistic children and hoped to make a career of it when she had finished her Navy service.

“I didn’t want her to join, but I was so happy she was stationed in D.C. because I was afraid it was going to be Afghanistan or Iraq — somewhere where she was going to get killed,” Alexander said. “And then this happened.”

At the trial, prosecutors said that Torrez was a predator who browsed Internet sites about rape fantasies and randomly attacked other women in Arlington after Snell’s death. He was convicted and sentenced in those incidents in 2010.

Torrez was charged in Snell’s death in 2011, linked to the slaying by boasts he made to a jailhouse informant and semen found on a bedsheet in Snell’s room. Prosecutors said at the trial that Snell, too, appeared to be victimized at random.

“We are standing here because Amanda Snell had the pure, dumb luck of having a room a few doors down from this man,” Assistant U.S. Attorney James Trump told jurors in his closing argument.

Defense attorneys said that although their client was flawed, prosecutors failed to prove him guilty of killing Snell. They noted that a military medical examiner testified that Snell had no injuries from a strangulation or a rape and that some of what Torrez bragged about to the informant did not match the case’s physical evidence.

Those attorneys now have to convince jurors that though their client has been found guilty, he does not deserve to die.

Jurors in the Eastern District of Virginia rarely impose the death penalty, even in the infrequent instances prosecutors seek it. Most recently, prosecutors sought the death penalty for three Somali pirates convicted in the fatal shootings of four Americans on a yacht off the coast of Africa, but jurors recommended they instead be sentenced to life in prison.

The last time a jury in the Eastern District recommended death was in 2009 for a man named David Runyon, who was convicted in a murder-for-hire plot in Newport News.

According to the Death Penalty Information Center, which tracks death penalty cases nationwide, Virginia has six inmates on federal death row.

Before the verdict had been returned, Snell’s aunt said that simply knowing that Torrez was in jail for life brought her comfort. She had returned to her home in Phoenix before jurors reached their decision and could not immediately be reached to comment Tuesday.

Torrez was discharged from the military in April 2010, a Marine spokesman has said. He is also charged in the 2005 killing of two young girls in his home town of Zion, Ill.

DNA evidence linked him to those slayings and forced prosecutors to drop charges against another man.

Torrez’s family declined to comment after the verdict. A federal judge ordered jurors to return April 21 for further presentations from both sides.

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