'Murder on Middle Beach' director says he 'wanted reassurance' that his family members weren't involved in his mom's death

• HBO's new documentary series "Murder on Middle Beach" follows Madison Hamburg, who's also the show's director, as he uncovers more about his mother's 2010 murder.
• Hamburg's sister and his aunt discovered the body of his mother, Barbara Beach Hamburg, outside of her Connecticut home.
• He told Insider that it was important for him to exonerate as many of his family members as he could, so that the family "can love each other unconditionally again."
• "We all want to know why she died," Hamburg added.

Madison Hamburg is in the unique position of being both the director of HBO's new documentary series, "Murder on Middle Beach," and the son of its subject, Barbara Beach Hamburg.

Hamburg was only 18 years old when his mother's body was found in 2010 outside of her Connecticut home when her sister, Conway Beach, arrived back at the home with Beach Hamburg's daughter, Ali.

Throughout "Murder on Middle Beach," Hamburg learns more about his mother's sometimes-contentious relationships with family members, including Beach and Ali.

Hamburg told Insider that it was important for him to exonerate as many families as possible while filming.

"I just wanted reassurance so that my family can love each other unconditionally again," he said. "We all want to know why she died."

"When getting involved with my documentary, they knew that there was going to be a level of sacrifice," Hamburg said of his family's participation. "I think...everyone started [participating] because they wanted to help me understand, and get through the grieving process, and understand my mom."

Along with Beach and Ali, Hamburg's great-aunt Jill Platt and his father Jeffrey are also featured in the documentary. His father, however, didn't appear on camera and instead was featured through surreptiously recorded audio.

Jeffrey was divorced from Beach Hamburg at the time of her death and had been accused by his ex-wife of failing to make alimony and child support payments in the months leading up to her murder. He was later considered a suspect in Beach Hamburg's case, but was never formally charged.

"There's no hard evidence that says that my dad did this," Hamburg told Insider.

And while the show does focus on finding Beach Hamburg's killer — thoroughly investigating Hamburg's father and other family members who might have had something to do with her death — the director said the most striking scenes involve quiet moments with family.

"Some of the most powerful scenes are just like me and my sister and a camera," Hamburg said. "When someone points the camera at you, it's like having a gun pointed at you."

"Your identity is on the line and I think that that is a part of the story, especially in true crime, that gets lost," he added. "The victims get lost, the families get lost in the crime and the details of the crime, and who the potential killer is overshadows a lot of the story."

"Murder on Middle Beach" premieres Sunday on HBO. You can watch the trailer below.