By Ozzy Hernandez and Catherine Potente
RIVERSIDE, CA – After weeks of preliminary hearings and delays, the murder trial of Mario Renteria officially began in Riverside Superior Court Wednesday morning with testimony from his former girlfriend and a sheriff’s deputy.
On April 9, 2018, the Riverside Fire Department responded to a car fire in Perris where they discovered the charred remains of an unidentified male adult. The victim was also shot to death before the car was on fire.
Renteria is suspected of being the perpetrator after authorities responded to a domestic disturbance just miles away from the incident. An hour later, Renteria was taken into custody.
Renteria is also accused of stealing the victim’s vehicle and then dousing it in flames. He is also charged with grand theft. 
In his opening statement, Deputy District Attorney Stephen Merrill quoted Renteria stating to authorities, “I killed for fun.” The defense made no opening statements.
DDA Merrill went on to suggest Renteria said he set the car on fire because he was trying to “clean up my mess.”
First to the stand was Renteria’s former girlfriend, who, according to her testimony, was with him for a year and half prior to the murder. They have two children together.
They were on and off in their relationship and were not living together at the time of the murder, said the witness, who recalled that on April 9 Renteria was acting “suspicious.” He parked a green Toyota on the side of the road “with no shirt and a gun to his waist,” she said.
Because of this, the witness called the police and was “in fear” of her safety.
Next to the stand was Riverside County Sheriff’s Deputy Gordon Mitchell, a 13-year veteran of the force who responded when a witness called 911 to report Renteria’s behavior April 9.
He recalled that day and the former girlfriend’s concern for her safety as well as her children’s.
Mitchell was at the scene with the green Toyota truck and then assisted his fellow deputies with a high-speed chase that was apparently related to the “burning car.”
Later, with Renteria’s cousin on the stand, DDA Merrill asked the witness about the incident that occurred on April 9, 2018.
Renteria’s cousin’s memory needed to be refreshed multiple times, stating, “It’s been so long, man.”
DDA Merrill referred to transcripts from the witness’s interview with a detective and read multiple accounts to refresh the witness’s memory. The transcript contained descriptions of what the witness had seen and told the detective who questioned him after the incident.
With a refreshed memory, the witness testified there were no prior signs of disagreement between the Renteria and the victim. Renteria asked the cousin to help him move the victim’s body and for money, but the witness refused, saying the incident did not involve him.
Renteria’s older cousin avoided any involvement in the incident due to prior felony history and current probation status in Riverside County.
The witness stated that instead of bringing the deceased victim to the hospital, Renteria planned to burn the body and leave for Mexico.
According to the witness, Renteria left the Riverside residence in a Honda vehicle that allegedly belonged to the victim.
During cross-examination, the witness stated he was inside the house all day and did not hear a gunshot coming from the shed in the backyard. The witness’s brother-in-law notified the witness of the incident in the shed.
The witness stated he could not testify with certainty that he knew exactly what occurred in the shed since he was in the house at the time of the incident. The witness only assumed he saw a human face wrapped up when he arrived at the shed.
The witness’s sister and Renteria’s other older cousin made the 911 call and instructed her brother to leave the residence with his brother-in-law due to his probation status.
Following a five-minute break, Emanuel Romero, a deputy sheriff for the Riverside County Sheriff Department was called to testify. On the day of the incident, Deputy Romero was assigned as a tactical flight officer within the aviation unit of the sheriff’s department.
The deputy responded to a call regarding a possible homicide and was notified of someone fleeing the location, noting, “My job is to observe and look for things out of the ordinary while we’re flying around [in the helicopter].”
Within three miles of the residence, a man in a black shirt standing outside the residence caught the deputy’s attention. The deputy reported seeing the subject in the black shirt enter a dark-colored car in the rear on the driver’s side. The subject left the residence with three other individuals.
While following the vehicle, Deputy Romero stated seeing the vehicle head east, adding, “The vehicle stopped really quick and made a quick left turn and almost immediately that back passenger door, where I saw the subject get into, opened up. Subject jumped out and the car took off.”
Officials located on the ground detained the subject and the deputy continued to follow the fleeing car.
During the cross-examination, Deputy Romero noted that he only heard information about a possible homicide from the call he received, but did not witness the incident occur.
DA Merrill called Captain Craig Rossi, a firefighter for the Cal Fire Riverside unit, to testify as an additional witness in the case.
Captain Rossi responded to a vegetation fire on the day of the incident, and testified that he and his team discovered a car in the middle of a field that was on fire and had lit the grass around it on fire. He identified the vehicle on fire as a Honda Civic.
After distinguishing the fire, Captain Rossi reported finding a deceased body in the trunk of the car. He roped the area off and relayed the information to the command center.
DA Merrill displayed a series of photographs to Captain Rossi where he identified seeing the skull of a deceased body in the photographs. Captain Rossi stated he had no knowledge of whether Renteria’s DNA was recovered from the scene.
Renteria’s other older cousin and sibling to the first witness was called next to testify as the fourth witness of the day. The witness had reported the incident to 911 and law enforcement that day.
When asked about family relations during her direct examination, the witness noted that family ties became distant after the incident occurred. The incident is not the topic of conversation.
“We don’t talk about much of what happened because I mean honestly only the three back there actually know exactly what happened, I mean. And I don’t like to give answers to things that I’m not aware of or don’t know, I don’t have answers to, you know, things that happened back there,” the witness stated.
The witness explained she was inside the house at the time of the incident and learned about the incident at the same time as her brother. With a shaky voice, the witness stated the call made to 911 was made out of concern for the victim.
Judge Mac Fisher followed up and stated, “I notice her dabbing her eyes and crying right now in response to the questions that mirror memory of the event.”
DA Merrill then asked for permission to play the 911 call in court that was made by the witness and the Judge Molloy approved of the request.
Judge Fisher detailed his findings from the 911 call, and stated, “[the witness] indicated concern relative to a shooting close in proximity to the time of the making of the call, she had a concern about the defendant coming back, she had knowledge of a gun, she felt the [the defendant] was acting oddly, she indicated, implied threats…and I believe I sensed hysteria in her voice.”
Judge Fisher concluded court proceedings for the day and will resume the witness’s testimony on Thursday at 9:30 a.m. in the same department.
