She had bruising on her arms, probably made by someone who roughly grabbed her. More bruises were on her back and stomach.

Even her fingers weren't spared. Assistant District Attorney Christopher Lalli said Crystal's fingernails were bitten to nubs probably because she was in such a state of stress during her short life. She also was suffering from the beginning stages of malnutrition.

"The pain must have been unbearable," Lalli said.

A Clark County jury will determine the fate of the two people authorities allege are responsible for Crystal's death in January 2006. Closing trial arguments, which began Monday, are set to continue today.

Jurors must decide whether Crystal's mother, Gladys Perez, 26, and former boyfriend Marc Anthony Colon, 30, should be convicted of killing Crystal in Las Vegas and leaving her body in a trash bin at the Villa Cordova Apartments on Eastern Avenue near Sahara Avenue.

Crystal's death sparked a nationwide effort to identify her. Authorities learned who she was about six weeks after her body was discovered.

During closing arguments Monday, Lalli said Colon delivered the blows that killed Crystal, who died from blunt force trauma to her torso. Prosecutors charged Colon with first-degree murder and will seek the death penalty if he is convicted.

Lalli also said Perez is guilty of first-degree murder. He said she failed in her duty to protect Crystal from Colon and helped cover up the killing when she later told relatives that Crystal was staying with other family members.

"They told lie after lie," he said.

He painted a picture of a woman who was so interested in keeping Colon as a boyfriend that she sacrificed her own daughter to please him.

"The last thing she would do is let (her) baby get in the way," he said.

If jurors find Perez guilty, they have the option of convicting her on either first-degree murder or second-degree murder, which is the inadvertent killing of someone during an unlawful act. But Lalli contends that Crystal died because Perez neglected her by not protecting her from Colon.

Peter Christiansen, Colon's attorney, said no evidence shows that Colon delivered the fatal blows to Crystal.

Christiansen maintained that Colon was innocent. Throughout the trial, Colon's attorneys shifted blame to Perez, saying neighbors testified that they heard Perez beating a child at a pay-by-the-week apartment where authorities think Crystal died.

Perez's attorneys said she was a victim of domestic violence who was helpless to stop the killing. One of her attorneys, Deputy Public Defender Tim O'Brien, said she was an insecure, lonely mother of two who was physically and emotionally abused by Colon. He described her as a whipped dog.

"We know who the wolf in the room is," O'Brien said. "It was Marc Anthony Colon calling the shots."

During closing arguments, Lalli played audio recordings of conversations by Colon and Perez. In one, an incarcerated Colon asks his daughter what she told police after he was arrested. She told police that he had abused Crystal, she said on the recording.

In another recording, Perez is heard expressing regret.

"I'm her mother. I was responsible for her," Perez said. "I have to pay for my ..."

Then the recording cut off.

Contact reporter David Kihara at dkihara@reviewjournal.com or 702-380-1039.