Shayley Estes, 22, was found shot to death in her Phoenix home on Friday, July 24, 2015. A recent Arizona State University chemistry graduate, she was discovered by her roommate after what police described as a brutal act of domestic violence.

Investigators quickly focused on her ex-boyfriend, Igor Zubko, a 26-year-old Russian national. Police arrested Zubko at Sky Harbor International Airport the evening of the murder; he reportedly had a one-way ticket to San Francisco. Authorities say Zubko had lived with Estes, she had recently ended the relationship and obtained a restraining order ten days before her death, and that he sent threatening text messages in the days prior.

Police allege Zubko used a key he had not returned to enter Estes’ apartment, waited for her return from work, and shot her multiple times as she tried to flee out the back door. A handgun and shell casings were recovered, and Zubko reportedly told police the shooting was an accident. He was charged with first-degree murder, burglary, and kidnapping; prosecutors announced they would seek the death penalty and bond was set at $1 million.

If anyone knew Shayley, her movements that week, or has information about the apartment’s locks or the restraining order, please come forward.