'This just doesn’t fit,' retired police detective weighs in on 1988 firefighters explosion

, Feb 24, 2022

KANSAS CITY, MO (KCTV) -- It’s been more than 33 years since an early morning explosion at a Kansas City construction site killed six Kansas City firefighters. It’s called the darkest day for the Kansas City Fire Department.

But even after all this time, questions remain as to what happened on that November morning. Earlier this month, a Department of Justice report was unsealed—allowing the first look at the report that was compiled eleven years ago. That report names two security guards as possibly being involved in the arsons. Jackson County Prosecutor Jean Peters Baker is calling those security guards “suspects” and is reviewing the case.

Our investigative team has combed through that report, plus hundreds of police reports, photos, and video. We connected with retired Kansas City Police Detective Victor Zinn, who was an investigator on this case for the KCPD. Questions about the incident, and the investigation still haunt Detective Zinn.

“The facts just don’t fit up,” said Zinn. “They don’t fit at all.”

Zinn interviewed one of the security guards, Debbie Riggs, hours after the explosion. KCTV5 has obtained that video.

Odd chain of events

In the police interview, Riggs tells the detective her version of the chain of events that morning. She told him that she was in her truck at the site, when she saw two men crossing a road, then they disappeared. She called her brother, Robert Riggs, who was in charge of security. He picked her up in his vehicle to search for the presumed prowlers. The two drove past where Debbie thought she saw them, shined a light, saw nothing, then drove to the nearby Quick Trip.

Debbie told police she left her truck, with the keys, purse, and gun inside and went to look for the prowlers.

“That struck me as odd,” said Zinn. “If I get down there, and the truck is running, keys are in it, I’m going to hop in. I’m going to take the truck! Or at the very least I’m going to take the purse. If I can see the gun and I’m a bad guy the gun is like a big chunk of gold or a big rock of cocaine. And they didn’t do that.”

Prowlers were never found. No one steals the truck with the keys and the purse inside, but someone does set it on fire. Police reports show the fire was “incendiary in nature. It is believed flammable liquid was introduced in the cab area.”

The purse contained Debbie Riggs’ identification. Despite extensive damage to the interior of the truck, the purse was only slightly damaged and the contents “were undamaged by the fire,” according to the police report. Her gun’s wooden handle is also only slightly damaged.

During the interview in the hours after the explosion, Debbie Riggs tells the detective after she and her brother came out the Quick Trip, they saw two separate fires.

Tips come in about truck fire

Police records reveal tips throughout the years documenting that Debbie Riggs wanted her truck destroyed for Insurance money. She was confronted about it in 1995.

She denied she had intentionally burned her vehicle. The detective advised her that information had been received that Donna Costanza, another security guard at the site, had burned the vehicle for her. Riggs denied any knowledge.

“She stated that Donna Costanza did not have the guts to set a vehicle on fire,” investigators wrote in the report.

Donna Costanza is the other person named in that newly-released Department of Justice report. Federal agents wrote that Constanza dated Debbie Riggs.

Debbie Riggs spoke with investigators numerous times. She passed a polygraph test and was never called a suspect. She’s now a grandmother living in Texas, according to Facebook.

Police spoke only briefly Donna Costanza on the day of the fire. There is no record of a formal interview related to the tips that she may have been involved. In fact, that newly-released DOJ report states, “Costanza does not appear to have been interviewed by law enforcement prior to the review team’s interviews.”

That means the first formal interview appears to be in November of 2009—21 years after the explosion. Federal agents also wrote in that report, “Costanza also stated that, prior to the evening of the arson and explosions, Riggs asked Costanza if she was interested in burning Rigg’s truck for insurance money. Costanza said that she refused.”

Detective Zinn told us that investigators “never got a good grip on (Costanza).” He said some of it was time and distance—it was hard to locate her. A combination of public records and Facebook reveals Donna Costanza now lives in Brooklyn.

KCTV5 has tried to reach both Debbie Riggs and Donna Costanza. Neither have responded to our requests for an interview.

Chasing other leads

For years, detectives and federal agents were chasing other leads. Some people pointed to union sabotage gone horribly wrong.

There were also tips implicating woodcutters, organized crime and even speculation of witchcraft and devil worshippers.

Police eventually zeroed in on five people from the nearby Marlborough neighborhood—brothers Frank and Skip Sheppard; their nephew, Bryan Sheppard; Frank’s girlfriend, Darlene Edwards; and Bryan’s best friend, Richard Brown.

The five were tried together and convicted. Skip Sheppard died in prison and Bryan was released in February of 2017 because he was only 17 years old when it happened. The other three remain in prison. All have professed their innocence.

When asked if he thinks all the people responsible for the blast are in prison, Detective Zinn answers simply, “Nope.”

“In my opinion, there are people walking around out there that shouldn’t be walking around,” said Zinn. He thinks the case should be reopened.

The families of the firefighters say that the constant questions mean there is no peace for them.

James Kilventon, the son of one of the firefighters told us in a previous interview, “I just want to get to the bottom of it. I mean I want closure. All the other families might think they have closure. I don’t have closure.”

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