Full Notification

Los Angeles County Sheriff’s Department Homicide Investigators are announcing the arrest of 31-year-old Andres Mateos for the murder of 34-year-old Oscar Medina-Partida and the attempted murder of a 34-year-old Hispanic female which occurred on May 12, 2025, at the intersection of 150^th Street East and East Avenue R in the Unincorporated Los Angeles Area of Sun Village in the Antelope Valley.  

On Thursday, October 16, 2025, Homicide Bureau detectives located and arrested Suspect Andres Mateos in the city of Rosamond in Kern County.  Suspect Mateos is being held on 4-million-dollar bail and was charged with one count of murder and one count of attempted murder.

For additional information or inquiries regarding this case, please contact the Los Angeles County District Attorney’s Media Relations at (213) 257-2000 or email them at [email protected].
     
There is no additional information at this time.

Forwarded by:  
Sheriff's Information Bureau 
Los Angeles County Sheriff's Department
211 West Temple Street
Los Angeles California 90012  
http://www.lasd.org    
213-229-1700  

FIRST UPDATE PRESS RELEASE:

Los Angeles County Sheriff’s Department Homicide Investigators are announcing they have identified the suspect in the murder of a 34-year-old Oscar Medina-Partida in the Unincorporated Los Angeles  Area of Sun Village in the Antelope Valley.  A 34-year-old Hispanic female was also shot and injured during the incident.  Andres Mateos, a 31-year-old male Hispanic, has been identified as the suspect in the murder and attempted murder.  A four-million-dollar arrest warrant has been issued for his arrest.   Detectives have exhausted all leads and are seeking the public’s assistance in locating Suspect Mateos.  Suspect Mateos is considered to be armed and dangerous and his whereabouts are unknown at this time.
 
On May 12, 2025, at approximately 9:30 pm, deputies from Lancaster Sheriff’s Station responded to in the intersection of 150^th Street East and East Avenue R in the Unincorporated Los Angeles Area of Sun Village in the Antelope Valley regarding an assault with a deadly weapon, gunshot victim at the location.  Upon arrival, deputies located Oscar Medina-Partida lying unresponsive in a nearby dirt lot, suffering from gunshot wounds.  The female victim had walked to a nearby fire station and alerted authorities of the incident.  Los Angeles County Fire Department personnel treated and transported the female victim to a local hospital.  They also responded to the location where Oscar was located and pronounced him deceased at the scene.   
 
Homicide investigators learned Suspect Mateos, and the victims were involved in an argument when Suspect Mateos armed himself with a rifle and shot the victims.  Suspect Mateos fled the location in an unknown direction.  
 
Homicide investigators presented the case to the Los Angeles County District Attorney’s Office for filing consideration.  One count of murder and a count of attempted murder was filed against Andres Mateos.  A four-million-dollar arrest warrant was issued.
 
The case is still being actively investigated and no further details about the case will be shared in order to maintain the integrity of the investigation. 
 
Anyone with information about this incident is encouraged to contact the Los Angeles County Sheriff's Department's Homicide Bureau at (323) 890-5500.
 
If you prefer to provide information anonymously, you may call "Crime Stoppers" by dialing (800) 222-TIPS (8477), use your smartphone by downloading the “P3 Tips” Mobile APP on Google play or the Apple App Store or by using the website http://lacrimestoppers.org

Forwarded by:  
Sheriff's Information Bureau 
Los Angeles County Sheriff's Department
211 West Temple Street
Los Angeles California 90012  
http://www.lasd.org    
213-229-1700  
 
ORIGINAL PRESS RELEASE:
 

DATE: Tuesday, May 13, 2025     
                            
REPORTED AT: 1:58 a.m.
                               
LOCATION: 150^th Street East / Avenue R in the city of Lake Los Angeles
 
VICTIM(s):  Male Hispanic Adult / Female Hispanic Adult
 
SUSPECT(s): Unknown
 
UNIT:  Homicide Bureau – Lieutenant Omar Camacho
 
NARRATIVE: 
 
Los Angeles County Sheriff's Department Homicide Investigators are continuing their investigation into the circumstances surrounding the death of a male Hispanic adult.
 
The Los Angeles County Fire Department notified Palmdale Station regarding a female Hispanic adult that walked into the Palmdale Fire Station with apparent gunshot wounds.  The female victim stated a male adult suspect fled the scene after the shooting and she indicated there was an additional gunshot victim at the location.  Lancaster deputies responded to 150th Street East and East Avenue R to investigate. Upon arrival, deputies located the male victim in a dirt lot, lying unresponsive with an apparent gunshot wound.  He was pronounced dead at the scene. 
 
The female victim was transported to a local area hospital for non-life-threatening injuries.
 
The investigation is ongoing.  There is no additional information available at this time.
 
Anyone with information about this incident is encouraged to contact the Los Angeles County Sheriff's Department's Homicide Bureau at (323) 890-5500. If you prefer to provide information anonymously, you may call "Crime Stoppers" by dialing (800) 222-TIPS (8477), use your smartphone by downloading the “P3 Tips” Mobile APP on Google play or the Apple App Store or by using the website http://lacrimestoppers.org
 
Forwarded by: 
Sheriff's Information Bureau
Los Angeles County Sheriff's Department
211 West Temple Street
Los Angeles California 90012 
http://www.lasd.org   
213-229-1700 
  
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Robert G. Luna, Sheriff
Los Angeles County Sheriff's Department