Father of Chiefs Fan Found Dead in Yard Speaks Out: ‘There Will Be a Wrongful Death Lawsuit’

David Harrington (center) with his grandfather, Rodney Harrington, and dad Jon Harrington .

“He loved life,” Jon Harrington tells PEOPLE of his son David

As families continue to wait for answers after three Kansas City Chiefs fans were mysteriously found dead in their friend’s backyard in January, one father says they’re already planning to take legal action.

Jon Harrington’s son, David Harrington, and friends Clayton McGeeney and Ricky Johnson visited Jordan Willis’s home on Jan. 7 to watch the Chiefs play against the Los Angeles Chargers. The three men were found dead outside their friend’s house two days later.

Harrington says his son’s death was a “big surprise.”

“He loved life,” Harrington says of his son. “I am incredibly sure that the outcome of this was not intended.”

Harrington says Kansas City Police read him the results of a toxicology report saying cocaine and fentanyl were found in his son’s body. (The autopsy and official toxicology reports have not been made public.)

Harrington doesn’t argue with the test results, but he wants to know how the drugs got into his son’s system, because he doesn’t believe his son knowingly or willingly took the drugs.

“I’m not buying it,” says Harrington, 57, who lives in Dearborn, Missouri, north of Kansas City.

To date, there have been no arrests or charges and the Kansas City Police Department has said “no foul play” has been “observed or suspected.”

The Kansas City Police Department Public Information Officers Alayna Gonzalez tells PEOPLE there have not been any additional updates released to the public. “Detectives remain in contact with Platte County Prosecutors and the victims family as the death investigation continues,” Gonzalez says, noting that the case remains a death investigation.

John Picerno, who represents Willis, previously told PEOPLE in a statement that his client “is unaware of how his friends died” and is “anxiously awaiting the results of the autopsy and toxicology report.”

Harrington last spoke to his son on Christmas Day. They had a long conversation and made plans to go out to dinner together in mid-January.

“He was a lot like me,” Harrington says. “When I would meet his friends, they’d say to me, ‘You look like David.’ I’d reply, ‘No, David looks like me. I was here first.”

He remembers his son as a stellar salesman who loved the Texas Longhorns and the Chiefs. He was physically strong, too. “I’m not a little man by any means, and David used to pick me up and twirl me around like a sack of potatoes,” his father says.

Jon and David Harrington. COURTESY OF JON HARRINGTON

On Sunday, Jan. 21, when the Chiefs — who went on to win the Super Bowl — played the Buffalo Bills, a celebration of life was held for David.

“I couldn’t have imagined a better way to send him off than that. There’s parts of that day that I will remember ‘til the day I die,” Harrington says.

The Chiefs game was on at the memorial and when the Chiefs scored at one point, “The entire crowd started chanting David’s name,” Harrington says. “That spelled sincerity to me.”

Despite talking with detectives and attending the meeting of victims’ families with the Platte County Prosecutor, Harrington says he still does not know what happened to his son — and that the toxicology report only raised more questions.

“I believe he intended to get drunk,” he says. “And particularly at his age, I couldn’t blame him. Couldn’t stop him. There’s none of that. But the [drugs] – I’m not buying that. I’m not arguing that that was what they found in his system, but how it got into the system, we still don’t know.”

David Harrington, Clayton McGeeney and Ricky Johnson. RICKY JOHNSON/FACEBOOK

As they wait for answers, the Harringtons have launched a T-shirt campaign, selling shirts to help keep the men’s names in people’s minds and their memories alive. A GoFundMe was also created to help David’s father.

Someday, Harrington says he would like to take legal action of his own.

“There will be a wrongful death lawsuit and a private investigator will more than likely be part of that,” he says.

In the meantime, he and other families have to wait until the criminal investigation is complete. “They can’t step on evidence or take evidence away from the criminal investigation,” he adds. “At this point, I don’t really know what to expect.”