Reiner and his wife, Michele, were slain earlier this month in their Brentwood home. Their 32-year-old son, Nick Reiner, is suspected of killing them, having been charged with two counts of first-degree murder. If convicted, he faces a maximum sentence of life in prison without the possibility of parole, or even the death penalty.

On Monday, Elwes, 63, broke his silence on Reiner’s death, sharing a moving tribute on Instagram alongside behind-the-scenes footage from The Princess Bride, including a sweet moment of himself and Reiner.

“Enough time has passed that I can finally put my grief into words. I was 24 when I first met Rob Reiner on The Princess Bride. And from that very first meeting I fell in love with him. I was already a fan of his work so meeting him in person was a dream come true. As we began spending more time together I knew this was someone I wanted in my life. I also knew that by casting me as Westley he was giving me the keys to the castle.”

“The first thing I noticed about Rob was that he wore his heart on his sleeve. This was a man who felt deeply. Whose heart was filled with love and compassion. He wasn’t impressed by how much money you had or if you had a privileged upbringing. He just wanted to know if you were a ‘good guy.’ He always tried to find the best in people. And if that person had problems he felt bad for them. He loved his family and friends immensely. He obviously loved making movies – and was clearly a brilliant filmmaker – but he told me what he really enjoyed the most was the experience itself.”

The actor went on to note what Reiner always “used to say”: “Once the movie is released it belongs to other people. But while you are making it, that’s your time on the planet, so you wanna make it good.”

“And boy was my time with him on The Princess Bride beyond great. I can’t remember a single day without laughter. The movie is about love, loyalty and sacrifice. Things that Rob held dear. Which is among the many reasons he was the perfect person to direct it,” he wrote, before then honoring Reiner’s late wife and their legacy together. “Later, while making When Harry Met Sally he met and fell in love with Michele. Besides being a gifted photographer she was an incredibly loving, intelligent person. Deeply passionate about her family and about lifting others up.”

“To say that they were a great team would be an understatement. Their only interest in fame was that it allowed them to shine a light on causes they believed in, especially helping those who were marginalized,” he added. “In a town where many talk the talk, they truly walked it. Whenever we got together we would talk about family, life, movies and politics. But without fail Rob would always find a way to make us laugh. That was important to him. Finding the joy.”

Elwes continued his post in the comments section, writing, “And if I could make him laugh in return, I felt like I had won the lottery. His laugh was one of the greatest sounds I’ve ever known — so heartfelt it still rings in my ears.”

He concluded his touching tribute by expressing his gratitude toward the couple and reflecting on his grief.

“Thank you Rob and Michele for sharing your life and art with us. Because my heart still aches every time I think of you, I know the grief of losing you too soon will likely never go away. Sure, death cannot stop true love but life is pain without you. ⚔️💔,” Elwes wrote. “With this note my family and I send our deepest condolences and heartfelt prayers to their family, friends and fans.”

Read his tribute in full in the post, above.