By CBSLA Staff

LAS VEGAS (CBSLA) – A man has been arrested on suspicion of murder in the beating death of his girlfriend in Las Vegas last week.

Justin Medof. (Las Vegas Metropolitan Police Department)

According to Las Vegas Metropolitan police, at 8:16 a.m. on July 12, officers were called to a motel on Dean Martin Drive off the Vegas Strip where they found a woman dead with a head injury.

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The victim was identified as 30-year-old Stephanie Duarte, a nursing student from the city of Orange.

“It’s been horrific and we never experienced anything close to this,” said Andrea Durate, the victim’s sister.

Her boyfriend, 31-year-old Justin Medof, a one-time Chapman University law student, was detained at the scene. Investigators discovered signs of a struggle inside the room, police said. It’s believed that she had been dead for a few hours prior to their arrival.

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Detectives learned the couple had gotten into an argument earlier in the night and then returned to the motel.

When officers arrived at the motel room, Medof was giving Duarte first aid, police said.

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Medof was booked into the Clark County Detention Center on open murder with no bail.

A memorial fund on GoFundMe for Stephanie Duarte’s family has raised over $57,000.