Rob Reiner and his wife Michele Singer Reiner's kids - son Jake and daughter Romy - broke their silence on the couple's tragic deaths and brother Nick Reiner's arrest in connection with their murder. "Words cannot even begin to describe the unimaginable pain we are experiencing every moment of the day. The horrific and devastating loss of our parents, Rob and Michele Reiner, is something that no one should ever experience," read the statement released to TMZ on Wednesday, December 17. "They weren't just our parents; they were our best friends." The statement continued: "We are grateful for the outpouring of condolences, kindness, and support we have received not only from family and friends but people from all walks of life." Rob and Michele's children requested privacy amid their brother's high-profile legal case. Rob Reiner and Wife Michele's Deaths: Everything We Know So Far "We now ask for respect and privacy, for speculation to be tempered with compassion and humanity, and for our parents to be remembered for the incredible lives they lived and the love they gave," they concluded. Rob and Michele married in May 1989 and shared sons Jake, 34, and Nick, 32, and daughter Romy, 27. Rob was also the adoptive father of his late ex-wife Penny Marshall's daughter, Tracy, 61. Rob Reiner, Michele Singer, Romy Reiner, Nick Reiner, Maria Gilfillan and Jake Reiner at 'Spinal Tap II: The End Continues' Los Angeles premiere. Michael Buckner/Variety via Getty Images Rob and Michele were found dead in their home in the Brentwood neighborhood of Los Angeles on Sunday, December 14. Us Weekly later confirmed that Nick was arrested and held without bail on suspicion of murder after his parents were stabbed to death. Following news of Rob and Michele's deaths, a spokesperson released a statement on behalf of the family. "It is with profound sorrow that we announce the tragic passing of Michele and Rob Reiner," the statement to Variety said. "We are heartbroken by this sudden loss, and we ask for privacy during this unbelievably difficult time." Tracy also spoke out on her own in the wake of the tragedy. "I came from the greatest family ever," she told NBC News. "I don't know what to say. I'm in shock." Prior to his parents' deaths, Nick publicly discussed his years-long battle with addiction. After Nick was accused of Rob and Michele's murders, sources told Us that amid his ongoing substance abuse issues, Nick had "always been hostile and volatile" toward his family. "Nick's problems have been going on for so long, so while everyone is in a state of shock right now, it's not entirely surprising," an insider said. Rob Reiner Family Guide: Wife Michele and 4 Kids, Including Tracy and Nick "A lot of his anger was directed at his parents for many, many years," the source continued. "They did everything a parent could possibly do to help him. Even in his younger years, they really tried to get him help. And then it became a cycle of seeking treatment for him, kicking him out, or him leaving the house, him moving back in. ... This went on for years." Romy, in particular, was "so traumatized by Nick's behavior," with the insider noting, "She has always been so close with her parents, and watching their constant pain over Nick has impacted her and the whole family so much." Of the effects of Nick's issues on the Reiner family, one source revealed, "It's been so much of their life." "Rob and Michele were honest about their struggles with Nick, and those who spent time with the family saw it firsthand," the insider told Us. "Everyone who knew them and loved them is struggling right now because it was never a secret." While the couple's friends are left wondering what they could "have done to help or to prevent this" outcome, a separate source insisted, "It didn't feel like an 'if' but only a matter of 'when' something catastrophic would happen." The Los Angeles District Attorney Nathan Hochman announced in a press conference on Tuesday that Nick has been charged with two counts of first degree murder. He is facing life in prison without parole or the death penalty. He appeared in court one day later but didn't enter a plea.