Homicide detectives have arrested a 36-year-old Anaheim man for the death of his ex-girlfriend, 24-year-old Mirelle Mateus, authorities announced Monday.  

The incident unfolded on Mar. 17, just before 2:30 p.m., when officers with the Anaheim Police Department were called to the 1900 block of South Union Street on reports of “suspicious circumstances at an apartment,” an Anaheim PD news release stated.   

Before police arrived, though, the gruesome discovery of the young woman’s body was actually made by her mother, Alice Mateus, who had desperately been looking for her daughter.  

“I opened to the apartment. I saw my daughter in the bathroom,” she said through tears. “I found her.” 

When detectives arrived at the apartment, they determined that the 24-year-old had been murdered and identified Aaron Romo as the suspect, police said. He was arrested later that day in Riverside County and booked at the Anaheim PD Detention Facility for murder. The 36-year-old is currently in custody and being held without bail.   

Family of the victim told KTLA that Romo had a history of abuse and that they had sought help from the courts and filed for a restraining order late last year. They believe the system failed them.  

“The system, it need to change,” Mateus’ mom said. “They need to change the system. How many more women in this situation?” 

Aaron Romo, 36, of Anaheim, was arrested on Mar. 17, 2023 and booked for murder in connection with the killing of 24-year-old Mirelle Mateus (Anaheim PD)
Aaron Romo, 36, was arrested on Mar. 17, 2023, and booked for murder in connection with the killing of 24-year-old Mirelle Mateus. (Anaheim PD)

Romo’s criminal history of domestic violence was ongoing, the latest issue stemming from a Dec. 5 incident with his ex-wife. The case was pending while he was out on bond.  

“He claimed to be suicidal, and I think that’s what my sister’s fear was,” Sandy Caceros, Mateus’ sister, said. “You know, that’s one thing she did mention to me, that her fear was for him to take his own life because she wouldn’t have been able to live with that.” 

The 24-year-old is remembered as a caring nurse who dreamed of traveling. The family has set up a GoFundMe campaign to help raise money for funeral expenses.  

“As angry as I am and as hurt as I am, I’m going to do whatever it takes to bring justice to her because it’s what she deserves,” Caceros said. “We got to put this man in there for the rest of his life and not be able to come out ever again and hurt anybody.” 

Because the investigation is ongoing, authorities did not elaborate on any evidence found at the scene, nor did they disclose a possible motive for the killing.  

“Detectives believe that Romo has assaulted other women in the past and are asking for anyone with previous contact with Romo to come forward,” the release noted.   

Anyone with information related to the homicide investigation or the suspect is asked to contact the Anaheim Police Department at 714-321-3669. Anonymous tips can be made through Orange County Crime Stoppers at 855-TIP-OCCS or online at Orange County Crime Stoppers