Victor Aureliano Martinez Ramirez, 29, was arrested four times before allegedly attacking and sexually assaulting a California woman earlier this month. Marilyn Pharis, 64, died on Saturday, eight days after police believe Ramirez, an undocumented immigrant, broke into her Santa Maria home, attacked her with a hammer and sexually assaulted her, Fox News reports

Pharis fought back during the attack, according to local ABC affiliate KEYT.

"We're proud of her because she fought back and she fought back enough that the police were able to identify her attacker," said Pamela Frame, Pharis' sister-in-law, told the news station.

Ramirez was arrested on the same day Pharis was attacked, July 24, trying to break into a nearby house. He pleaded not guilty to attempted murder, first-degree burglary with person present, assault with intent to commit rape, sexual penetration by foreign object and resisting a peace officer on Friday, but now he may face murder charges in light of Pharis' death, according to the Santa Maria Times.

Although Ramirez is an undocumented immigrant, Santa Maria police say that bears little importance on the case. They are focused on completing the investigation.

"We have a citizen that lost her life, it's serious, when you look at it, we don't care what the circumstances were, we're going to do what we need to do to get our facts and bring this individual to justice," Santa Maria Police Department Commander Kendall Greene said. "If there are extenuating circumstances that arise as a result of that, that he's an undocumented immigrant, then we will let the proper authorities address those issues when they present themselves."

All four of Ramirez's past arrests were by the Santa Maria Police Department for minor crimes. Prior to last month he was most recently arrested in 2014.