JOHNSTOWN, Colorado (AP) -- Two teens have been charged with killing the 7-year-old sister of one of them by beating her with imitations of moves from the "Mortal Kombat" video game, prosecutors said.

Lamar Roberts, 17, and Heather Trujillo, 16, were charged as adults on one count each of felony child abuse causing death, state prosecutor Robert Miller said in court documents released Wednesday and filed a day earlier.

According to a police affidavit, the teens were baby-sitting Trujillo's half-sister, Zoe Garcia, on December 6 while the girl's mother was at work.

Zoe lost consciousness and stopped breathing after the teens hit, kicked and body-slammed her, imitating moves used in the video game, the document said.

Trujillo and Roberts tried reviving the girl by putting her under running water and attempting CPR before they called her mother and 911, the affidavits stated. The girl died at a hospital.

An autopsy showed she had a broken wrist, more than 20 bruises, swelling of the brain, and bleeding in her neck muscles and under her spine, the affidavits said.

Sheriff's spokeswoman Margie Martinez said late Wednesday that she did not know whether either teen had an attorney. The teens were being held at the Weld County jail but were not permitted to accept phone calls, Martinez said.

Roberts said he was downstairs playing video games while the sisters wrestled upstairs, police said. But a witness quoted in the affidavit said Roberts told her he had kicked the girl.

The witness told police that Roberts said Zoe had told them to stop wrestling. According to the affidavit, when the witness asked why they didn't stop, he responded, "I don't know; I was drunk."

If convicted, the teens could be sentenced to 48 years in prison.