 When this mother saw her new baby's face, she immediately knew that he wasn't hers. When Richard Cushworth and Mercedes Casanelas welcomed their first child, a little boy, in May 2015, the couple were understandably over the moon. And after Casanelas had given birth in her home country of El Salvador, she returned to the United States with her baby in tow, ready for the start of a brand new chapter in her life. But what should have been a happy period for the mom ultimately became a nightmare? As she watched her son grow, she became convinced that he wasn't hers. Both Cushworth and Casanelas had experienced struggles before this point though. Cushworth, 4-1, had spent some 20 years battling substance abuse, including a reliance on alcohol, cocaine and heroin. But he had finally turned things around after attending Teen Challenge, a rehab program with a Christian focus. Then, after finding God, Cushworth had gone to Bible school at the Christ for the Nations Institute in Dallas, Texas. It was here that he first met Casanelas, who was attending the evangelical organization as a foreign student. And after the couple married in 2012, they traveled to Casanelas' native El Salvador to work as missionaries. Yet although Cushworth had both managed to conquer his addictions and find love, his troubles were far from over. You see, while he was in El Salvador, the apartment he'd been renting in Dallas was gutted by fire and decimated his possessions. Casanelas, meanwhile, had had to come to terms with being attacked by a gang with guns shortly before her move to the United States. Then, finally, Cushworth and Casanelas returned to the US, settling in Dallas once more. When the birth of her first child was imminent, however, the mom-to-be went back to El Salvador. She would welcome her son at a hospital that was thought of as one of the best private health facilities in the country. And after Casanelas delivered her baby Jacob via emergency caesarean, she was handed the newborn briefly. Recalling that special moment in a 2016 interview with the BBC, the mother said, Jacob, was just passed by me, and I gave him a kiss. And then he was taken to the nursery, and that was the last time I saw him. The following day, nurses returned Jacob to Casanelas. Then, when the little boy was four days old, Casanelas left the hospital and reunited with Cushworth, who'd flown in from Texas. The trio went on to spend three months in Central America, before returning as a family to their home in the States. But while Casanelas bonded with her baby as the weeks and months passed, she still struggled to shake a niggling doubt from her mind. In particular, she felt that Jacob didn't look like either her or her husband, and this led her to wonder whether her son was really theirs. Casanelas' first suspicions had emerged in the hospital, when Jacob had been handed to her the day after his birth. She later told the BBC, when I saw Jacob, the first impression was, this is not the same baby that I saw last night. I looked at him, and I remembered that the baby that I saw was just like my husband, and this baby did not look like my husband. Yet while Casanelas had raised her concerns to the hospital staff, they had assured her that the baby she'd been given was definitely hers. To further ease the new mom's worries, nurses told her that she'd been heavily medicated when she'd briefly seen Jacob for the first time. In other words, she couldn't rely on the first memory she'd had of her child. So with the medical professionals telling Casanelas that she definitely had the right child, she had little choice but to believe them. Even so, she continued to ask her friends if they thought there may have been some kind of mix-up with her baby. And, yet again, everyone assured the mother that Jacob was hers. For a little while, then, Casanelas tried to put her worries to the back of her mind. But they didn't stay buried for long. In Casanelas' interview with the BBC, she said of Jacob, the days started to go by, and his features, his skin, everything started to change. And he started to not look anything like either one of us. At this point, Casanelas' feelings for Jacob were confusing. She explained, I was nursing the baby. I was taking care of him, loving him like ours, and I started to fall in love with the baby. You love this baby like your baby, but then inside, I had the thought, what if this is not my baby? Painfully, Casanelas tried to ignore the doubts about whether Jacob actually belonged to her and Cushworth. She even kept her worries from her husband, who had no idea that his spouse was wrestling with the idea that their son may not be theirs. Instead, the new mom secretly took a DNA test to get to the bottom of the matter once and for all. And when the DNA results came back, Casanelas discovered that there was absolutely no genetic link between her and Jacob. Tragically, she'd been right all along. Describing her reaction, Casanelas told the BBC, I just fell on the floor. Fighting back tears, she added, there was, the pain, the thought that the baby I had been nursing, taking care of, loving him, baiting him, that he was not mine. Then, as the missionary tried to process the news, her thoughts turned to the child she'd given birth to back in El Salvador. What had happened to that baby? An emotional Casanelas later told the BBC, I had two thoughts. What is going to happen with this baby, and where's my baby? When Cushworth found his wife crying on the floor at home, though, he had no idea what had happened. And to begin with, Casanelas didn't know how she would break the news to him about Jacob. She told the BBC, I couldn't even speak for minutes and minutes. Finally, Casanelas told Cushworth about the DNA test, and what it had uncovered. And revealing his reaction to the news, Cushworth told the BBC, I was just overwhelmed and confused. I didn't even know how to process it. I remember the first trauma to me was, oh my goodness, I have a child, and my child is somewhere out there in the world. Where is he? Prior to the bombshell DNA test, Cushworth had no inkling that Jacob may not have belonged to him and Casanelas. He explained, I just accepted him as my child. Now I look back at the pictures, right around the time that we came to Dallas when he was three months old, and I'm shocked that I never suspected, because you can see that it's just obviously not my child. Using the benefit of hindsight, Cushworth continued, I don't know how I didn't ask myself. You just, you don't think about these things. His wife added, we were in love with the baby. Even when I did the DNA test, I thought that I was betraying him. She noted, however, that she simply couldn't have lived with the doubts she'd had over Jacob's parentage. And like Casanelas, Cushworth had a multitude of questions regarding his biological child's whereabouts. Recalling some of these to the BBC, he asked, where is he? Who's taking care of him? What happened to him? Why did this happen? Am I ever going to see him again? The father went on, I just felt like a panic that my only child was lost or stolen. I didn't know what it was, and that was the concern. Cushworth pondered, too, whether the baby they were raising may be taken away from him and his wife. And while he and Casanelas had initially had faith that they may be able to keep both boys, the couple knew in their heart of hearts that this was probably impossible. The new father explained to the BBC, our hope, in the beginning, was that we would find our real child, and that, we would also be able to keep the one that we had raised for three months. In that way, we would have two children. But I remember that I was the first one who started saying, you know, if this child has a legitimate family, we're going to have to give him away. It seemed likely, too, that Jacob had been mistakenly given to Casanelas the morning after his arrival. So, to get to the bottom of the mix-up, DNA tests were carried out on the children who'd been born at the hospital in El Salvador on the same day as Jacob. And that's how Casanelas and Cushworth found their biological child. But the couple's joy at being told their son had been found was mixed with feelings of grief that they would have to give up Jacob, whose biological parents had also been identified. And Casanelas recounted how she handed over the child she'd grown to love in her emotional interview with the BBC. As tears fell down her face, Casanelas recalled, we got there, and we had to rush. We were rushed in. We have to go quickly, just bring the baby, and we barely got time to say goodbye. I got all his clothes, and we took him in the office, and we handed him in. And that was the most difficult part, I think, of the whole situation. Still, while the pair were heartbroken to be handing over Jacob, they were also overjoyed to finally reunite with their real son. Recalling that moment, Casanelas told the BBC, we finally saw him, and when he saw us he was smiling, he was laughing. There was a moving coincidence that the parents couldn't explain, too. When the couple had swapped Jacob for their son, both babies seemed to slot right into their real families. Casanelas explained, we didn't know, the other parents, we don't know anything, but the babies, when we took them, and we switched, they each were dressed like their fathers. It was really nice. Casanelas and Kushworth subsequently named their biological son Moses, a nod to the Hebrew prophet, who is said to have also been missing for three months. And the couple insisted that their faith had helped them get through the whole episode. Kushworth told the BBC, God has helped us and comforted us through the process. Still, the parents or deal wasn't over. You see, before Casanelas and Kushworth could leave El Salvador and return with Moses to the States, they needed to first produce a birth certificate for their son. And obtaining this documentation proved to be a lengthy process for the family. In order to locate the correct records, then Kushworth, who was born in the United Kingdom, turned to the British Embassy for help. He was assisted by Ambassador Bernhard Garside, who would later tell the BBC that the swapping of the babies was the easy bit in comparison to what had followed. Garside explained, when we first got involved, it looked very much like an uphill struggle. My fear was that we weren't really going to see a happy conclusion to this. However, with some old-fashioned diplomacy, he was able to help the couple navigate the Salvadoran court system. In 2016 Garside revealed to the BBC what took time was unraveling the legality of all the birth certificates and making sure the right parents were recorded with the right children. Ultimately though, the parents' efforts finally paid off and the Ambassador was happy to have helped. In fact, Kushworth would go on to refer to him as an angel. Speaking to British newspaper The Independent in 2016, Garside further explained the trickiness of the situation. He said, from a family perspective, this has been very, very tough. This is every parent's nightmare. The bureaucracy of the El Salvadoran system always seemed to conspire against them, but with the help of the Supreme Court judge and some good old-fashioned diplomacy, we finally managed to get leverage, and we got the result we wanted. So, while the process had taken three-quarters of a year, and almost all of Casanelas and Kushworth's money, they finally got to take Moses back to the States in summer 2016. And as Jacob's family received his birth certificate at the same time as the American citizens got hold of Moses' official papers, the two sets of parents used the opportunity to meet once more. Kushworth revealed to the BBC, we spent about two hours with the other family, took a lot of pictures and videos. Then, when he and his wife were asked whether they'd like to remain a part of Jacob's life, the dad responded, I think so, and I would certainly hope so. Casanelas added, we would like that. In the meantime, the parents continued to bond with their son, making up for the time they'd lost in his first three months. Casanelas later revealed of that period, it was beautiful, it was a blessing of God. I got to nurse Moses too without any problems. He adjusted, he never cried. He was very peaceful and happy and smiling. All the while, the couple were still awaiting answers as to how their child had been mixed up with another in the first place. Garcide has revealed, however, that the Salvadoran authorities have concluded their investigations and found there was no criminal element involved in any of this. It was simply a mistake. This conclusion did little to address Casanelas and Kushworth as many unanswered questions. Kushworth told the BBC, I really would love to see justice in this situation. I'd like to know what happened. How did this happen? Because I don't want to see it happen to another person. And as the truth behind the mix-up still eluded Casanelas and Kushworth, all they could do was to assess the difficulties they'd faced and try to move forward. Kushworth explained, it's done terrible financial damage and emotional damage to us. But we're here, we survived. Everything is turning out okay.