Quinnipiac University Public Safety Captain Don DiStefano was featured in the Netflix documentary, “This is the Zodiac Speaking,” — a documentary detailing the leading suspect of the unsolved case of the Zodiac Killer — released on Oct. 23. 

The documentary explains that the case of the Zodiac Killer is one of the most famous unsolved cold cases in American history. The Zodiac Killer murdered at least five known victims in 1968 and 1969 in the San Francisco Bay area. In 1971, Arthur Leigh Allen became the only named suspect in the case. The documentary follows the investigation of Allen and his ties to the Zodiac. 

In the documentary, DiStefano discusses his role as a detective on the case as well as his experiences throughout. 

“When this first happened I was seven years old,” DiStefano said. “And then who would have known years later, I would be a detective in Vallejo, California that had a real Zodiac homicide case.”

The New York native started his career working for the Alameda Police Department in 1985. He later transferred to the Vallejo Police Department in August 1990. 

In 1992, as a new detective in the Investigations Bureau, DiStefano had his first experience with the Zodiac case. After a search warrant was filed for Arthur Leigh Allen’s home, he was brought into the Vallejo station for questioning. 

As a member of the Detective Division, DiStefano was asked to escort Allen into the interview room and wait until other detectives were ready to interview him. 

“He was quiet. We didn’t really say anything to each other,” DiStefano said. “He was cooperative, and he was cordial and just relatively calm.”

This was DiStefano’s first interaction with someone who was possibly a serial killer. It was also a moment of realization for DiStefano, in that he could be face-to-face with the real Zodiac. 

“And it hit me, ‘Wow,’” DiStefano said. “This is possibly, you know, the Zodiac serial killer.” 

In 1998, the detective leading the Zodiac case left the agency, and DiStefano was assigned the case. His supervisor gave him a box of letters from people all over the world who thought they knew who the Zodiac was. The agency received several letters a month.

“He actually came over to me with this big box that he kept under his desk, and kind of plopped it on my desk and said, ‘Okay, here it is. Good luck,’” DiStefano said. 

From then on, anything Zodiac-related went through DiStefano. Though the investigation was inactive, DiStefano had to be ready to investigate any new tips. 

Around 1999, the case gained a lot of media attention. Sony Pictures and Phoenix Pictures began filming the movie  “Zodiac,” released in 2007. 

Vallejo Police was later approached by Sony and Phoenix around 2004 for a liaison from the police department while making their movie. DiStefano then worked with researchers during their initial research. 

“They approached all of the agencies in the San Francisco Bay area that had bonafide Zodiac murders, and asked for access to all the case files and evidence items,” DiStefano said. 

This kickstarted the creation of the Zodiac Task Force. DiStefano was asked to head the team as Vallejo police were the most transparent about the case. 

“I got all the investigators that were like me that had the Zodiac case at that moment together, and we met numerous times,” DiStefano said. “We had at least one meeting a month. And really the goal was to take a fresh look at this.”

The task force looked at evidence with forensic technology that was not available to detectives at the time of the murders. They organized case files and read through reports to try to find any new leads. 

Each department had evidence items buried in warehouses or storage areas, creating the task of finding and reorganizing all of the evidence, before taking it into a lab for forensic analysis. 

“Law enforcement was using the DNA technology to either eliminate someone from suspicion or include someone and connect them to the crime,” DiStefano said. “A lot of the agencies still had the original bullets that were removed from the victims bodies, casings that were at the crime scenes. So there were new forensic techniques available in the 90s to examine those items for evidence.”

After about a year and a half, the task force accomplished its goals but did not develop any new leads or suspects. 

After retiring from Vallejo in 2005, Phoenix Pictures hired DiStefano as a consultant to finish working with their researchers. 

Having worked with Phoenix, DiStefano landed on Ample Production’s radar when they began their documentary, “This is the Zodiac Speaking.”

DiStefano received that call on July 4, 2023, which was coincidentally the anniversary of the Vallejo murders that took place in 1969. 

“I hadn’t really thought about the case in over 20 years,” DiStefano said. “It was like the furthest thing from my mind.”

Ample Productions flew DiStefano out to Los Angeles, covering his hotel, meals and transportation. He was scheduled to be there for two days and was interviewed in a set made to be an old detective office from the 1960s. 

DiStefano was not prepared ahead of time about any of the questions he was asked. Instead, he read through reports up until he entered the studio. 

“I was reading these reports over and over again, because I wanted to do a good job,” DiStefano said. “I wanted to be accurate and come across well.”

Inside the studio, several different people interviewed DiStefano. Behind the camera also sat a large production team, with those on lighting, cameras and more.

“It was really easy, and I felt very relaxed and comfortable doing it,” DiStefano said. “It wasn’t the first time that I was in front of a camera, but it was the first time I was in front of a camera for a long time. 

For both days he was there, DiStefano spent all day in the studio. He was then brought back two weeks later, to spend another two days being interviewed. 

“Everybody was great. And you get to know these folks and build a rapport, and we had a really good time,” DiStefano said. 

When the documentary was released, DiStefano and his family gathered to all see it for the first time, on Oct. 23. 

“So on the night of the 23rd after I came home from work, got the whole family together, and we all watched it together in the living room for the first time. So it was the first tine I saw myself,” said DiStefano. “I was very happy with how it came out.”

Looking back years after working on the case, DiStefano never thought he would have been working on an infamous case like this. 

“I was very happy to be working on it and it was a great experience,” DiStefano said. “Looking back now, maybe I didn’t realize how famous of a case it was at the time I was working on it, but that’s a good thing because it didn’t interfere with how I tackled it.”