A Los Angeles-area youth soccer coach accused of murdering a 13-year-old boy had previously been investigated for child sex abuse, prosecutors have revealed. Mario Edgardo Garcia Aquino, 43, is facing charges of murder with special circumstances in the death of Oscar Omar Hernandez, whose body was found dumped on the side of a road in Oxnard, California. But police records obtained by the Los Angeles Times show Garcia Aquino, an illegal migrant originally from El Salvador, was the subject of two earlier investigations into alleged sexual abuse of children. The Los Angeles Police Department had previously investigated him back in 2022 for allegedly sexually assaulting a minor - but he was never charged because the alleged victim declined to testify against him, multiple law enforcement sources told the paper. However, on Tuesday, prosecutors amended the criminal complaint against Garcia Aquino to include one felony count each of assault with the intent to commit a sexual offense and lewd act upon a child 14 or 15 years old. Prosecutors explained that the charge stems from a sexual assault on a teenager at his then-home in Sylmar on December 10, 2022. Additionally, Garcia Aquino has been charged with a felony count of assault with intent to commit a lewd act against a 16-year-old boy on February 22, 2024 in Palmdale. Both of those victims, along with Hernandez, were connected to his soccer coaching at the Hurricane Valley boys' soccer club in Sylmar, where he worked with different age divisions. But the alleged sexual assaults only came to light after Hernandez's body was found near Leo Carillo State Beach - with Los Angeles County District Attorney Nathan Hochman explaining at a news conference that the delay in filing the charges for the 2024 incident is because such crimes must be thoroughly investigated. While that investigation was continuing, Hernandez's family reported him missing on March 30 - saying he failed to return home from visiting Garcia Aquino, his soccer coach, at his Lancaster home. The teenager had taken a train to the Antelope Valley the day before, and his family told NBC Los Angeles they believed he was simply being paid for odd jobs at the coach's property. But when Hernandez's brother tried to call him later that day, Garcia Aquino answered his phone and said the boy was busy and could not talk. Eventually, Daniel Hernandez - the boy's father - also called the coach and insisted that he drop the teenager off near the family's home, which never happened. Following his disappearance, police used data from cellular devices, cellphone towers and other tracking systems to determine that Garcia Aquino visited the Oxnard area. An ensuing search by the Los Angeles Police Department and the FBI led to the discovery of the boy's body alongside North Harbor Boulevard. The boy's cause of death remains unclear, as friends raise money for his grieving family, netting more than $23,000 for them as of Wednesday. They have described the teen at a vigil as the 'nicest person.' 'He was just trying to have his own money and accomplish his goals in life,' one friend said, according to ABC 7. Melanie Samayoa, 12, also said Hernandez 'was always kindhearted.' 'He had such a great personality, he was funny,' she described. 'He would always bring out a smile to us, and like one of my friend's said he's such a great dancer, too.' Prosecutors are now working to determine 'whether or not the death penalty is appropriate for this particular case,' ABC 7 reports. If the District Attorney's Office declines to seek the death penalty, Garcia Aquino could still face life in prison without the possibility of parole in addition to a potential six years in prison for the alleged assault. The suspect has not yet entered a plea in any of the cases, and it is unclear whether he has retained a lawyer who could speak on his behalf. But the Department of Homeland Security has labeled him a 'depraved illegal alien who should have never been in this country' in a post on X. 'Under President Trump and Secretary [Kristi] Noem's leadership, child predators, pedophiles and murderers will be hunted down and removed from America's communities,' it vowed. Similarly, US Attorney for Los Angeles Bill Essayli issued a statement, saying Hernandez's death 'was an avoidable crime and the result of failed border policies. 'We cannot and will not tolerate illegal aliens who flout our nation's immigration laws then prey on children,' he said. 'Federal law enforcement will continue to be very aggressive in locating, apprehending and prosecuting criminal illegal aliens.