The fate of a former U.S. Marine charged with killing a fellow service member at Joint Base Myer-Henderson Hall now rests with 12 jurors in federal district court in Alexandria.

After hearing four days of testimony last week, jurors on Monday listened to prosecutors and defense attorneys make their final pitches in the case against Jorge Torrez, who is charged with first-degree murder in the 2009 death of 20-year-old Amanda Jean Snell.

Prosecutors argued Torrez, 25, is something of a sexual predator who snuck into Snell’s room in a barrack at the Arlington, Va., base, strangled her with a laptop cord and then stuffed her body in a wall locker. Base staffers found it days later, after Snell failed to show up for work.

Defense attorneys acknowledged their client was in Snell’s room — his semen, after all, was found on one of her bed sheets — but they argued that prosecutors could not describe precisely what happened between the two.

Prosecutors are seeking the death penalty against Torrez, but for now jurors are considering only whether he is guilty of murder. They left the courtroom for lunch and began deliberating shortly after 1:15 p.m.

Prosecutors argued that the evidence against Torrez was “overwhelming.” They noted that Torrez confided to a jailhouse informant that he killed the young Navy petty officer, and in a tape-recorded conversation, he revealed details of the crime that were not widely known.

Snell, they said, was found dead in the wall locker in the position Torrez had described, wearing the clothes Torrez described. Investigators also found Torrez’s semen on a bed sheet in Snell’s room, contradicting his repeated claims that he did not know Snell and had never been inside her room.

“The evidence of the defendant’s guilty is simply overwhelming,” Assistant U.S. Attorney Jonathan Fahey told jurors in his closing argument. “He went in to her room while she was sleeping. He choked her. He strangled her. He murdered her.”

Prosecutors painted Torrez, too, as a sexual predator, one who browsed Internet sites about rape fantasies, had experience in choke-holds and randomly attacked other women in Arlington after Snell’s death. They said he did not know Snell, who lived several doors down from him in a barrack known as Keith Hall.

“It was a sexually motivated attack,” Assistant U.S. Attorney James Trump told jurors. “We are standing here because Amanda Snell had the pure, dumb luck of having a room a few doors down from this man.”

Torrez is now serving five life sentences plus 168 years at Virginia’s Red Onion State Prison stemming from the other attacks in Arlington. He was convicted and sentenced in those in 2010. He was charged with first-degree murder in Snell’s death in 2011.

Defense attorneys said that while their client was no saint, prosecutors had failed to prove him guilty of killing Snell. They noted that a military medical examiner testified that Snell had no injuries from either a strangulation or a rape, and he could thus not even rule her death a homicide. They argued, too, that Torrez’s story to the informant was riddled with inconsistencies, and some of what he described did not match physical evidence in the case.

“Something happened between Mr. Torrez and Miss Snell. Unfortunately, we just don’t know,” defense attorney Robert Jenkins told jurors.

If Torrez is convicted of first-degree murder, jurors will convene again later this month to determine whether he should be sentenced to death. The last time jurors in the Eastern District of Virginia recommended such a punishment was in 2009 for David Runyon, who was convicted in a murder-for-hire plot in Newport News. More recently, prosecutors wanted 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 that they instead be sentenced to life in prison.

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.

Get updates on your area delivered via e-mail