How two St. Louis homicide detectives pursued a complicated murder investigation that eventually led to a conviction nearly eight years after the killing.
ST. LOUIS, MO – October 27, 2026 (TheBrighterSideofBlue) When the body of 36-year-old Dominic Smith was recovered from the Mississippi River in September 2015, St. Louis homicide detectives faced a disturbing murder investigation with few straightforward answers.
Smith had been shot, his body concealed inside a bag intended for a musical instrument, and his remains dumped into the river. Weeks later, his decomposed body was discovered caught on a barge.
The circumstances presented investigators with a difficult question: Who had killed Dominic Smith, and how could detectives establish what happened?
For former St. Louis Metropolitan Police Department (SLMPD) homicide detective Mark Biondolino and his partner, Detective Mike Herzberg, the investigation would involve conflicting leads, suspected criminal associations, an unexpected development in another murder investigation, and the discovery of shotgun components concealed in concrete near South Broadway.
The case eventually resulted in a guilty plea and a 20-year prison sentence.
More than a decade after Smith’s murder, Biondolino revisited the investigation in an October 27, 2026, episode of The Brighter Side of Blue Podcast, offering listeners a closer look at the investigative challenges behind one of St. Louis’ more unusual homicide cases.
The episode, titled The Murder of Dominic Smith: A Cold Case and a Concrete Clue, explores how detectives navigated misleading information and followed an unexpected lead that helped identify the killer.
A Murder Investigation Begins on the Mississippi River
In September 2015, Dominic Smith’s body was discovered in the Mississippi River near South Broadway in St. Louis.
According to police information reported by KMOV, Smith had been fatally shot. Following the killing, his body was placed in a bag designed for a musical instrument and dumped into the river.
His remains were discovered several weeks later.
The passage of time between the killing and the discovery complicated the circumstances surrounding the investigation.
Recovering a body from a river can create substantial challenges for homicide investigators. Water exposure, decomposition, and the possibility that remains have moved from their original location can make reconstructing events more difficult.
The location where a body is discovered may not be the location where a homicide occurred.
Detectives must therefore work backward, examining the victim’s last known movements, personal relationships, potential witnesses, and available physical evidence.
In Smith’s case, the investigation required determining not only who had killed him but also how his body came to be concealed and disposed of in the Mississippi River.
The circumstances suggested that someone had taken deliberate steps to hide the crime.
Detectives Biondolino and Herzberg Take the Case
Former SLMPD homicide detective Mark Biondolino and Detective Mike Herzberg were assigned to investigate Smith’s murder.
According to the podcast’s published account, the detectives encountered a complicated network of rumors, conflicting tips, individuals associated with St. Louis’ South Side, and suspected connections to a Missouri prison gang.
These potential leads challenged investigators trying to separate credible information from speculation.
A homicide investigation can generate numerous statements from individuals who claim to know what happened.
Some information may be accurate. Other accounts may stem from rumors, misunderstandings, or personal disputes.
Investigators must determine which details can be independently corroborated.
Suspected criminal associations do not establish responsibility for a particular offense, and investigators must avoid letting a person’s reputation substitute for evidence.
For Biondolino and Herzberg, the difficulty was identifying information that could move the investigation toward a defensible conclusion.
The podcast describes numerous leads that failed to produce an immediate resolution.
Despite the volume of information available, detectives struggled to determine who had killed Smith.
The investigation remained unresolved as the months passed.
When Investigative Leads Fail to Produce Answers
Homicide investigations do not always advance in a straight line.
Detectives may receive information that initially appears promising but ultimately cannot be substantiated.
Witness accounts may conflict. People may be reluctant to cooperate, and investigators may encounter information that raises more questions than it answers.
In some cases, time creates new obstacles.
Witnesses relocate. Memories become less reliable. Relationships change, and physical evidence may become increasingly difficult to locate.
However, time can also produce new investigative opportunities.
Individuals who previously withheld information may decide to cooperate. Developments in unrelated investigations may reveal previously unknown connections.
The Dominic Smith case would eventually demonstrate the importance of that possibility.
More than a year after the murder, an unexpected development in another criminal investigation provided information that changed the direction of the case.
A December 2016 Breakthrough
According to The Brighter Side of Blue Podcast, a confession that emerged during an entirely different murder investigation in December 2016 became a turning point in the investigation into Smith’s death.
The development came approximately 15 months after Smith was killed.
The podcast describes the confession as the breakthrough that finally helped investigators identify the killer.
The published episode summary does not provide a complete transcript of the confession or independently establish every investigative step that followed.
Nevertheless, the reported connection between the two investigations is significant.
Homicide detectives frequently work cases involving overlapping individuals, relationships, locations, and criminal allegations.
Information discovered during one investigation can sometimes become relevant to another.
An individual questioned about one crime may disclose information concerning an earlier offense.
Investigators must then determine whether the new information is reliable and whether other evidence supports it.
In Smith’s case, the December 2016 development reportedly gave detectives the direction they needed after months of uncertainty.
It also led to one of the most unusual elements of the investigation: the discovery of shotgun components concealed in concrete.
A Shotgun Hidden in Concrete Near South Broadway
One of the defining details of the Dominic Smith murder investigation involved the concealment of the shotgun used in the killing.
According to KMOV’s May 2, 2023, reporting, police said that after shooting Smith, Peter Chafin concealed the shotgun in cement and left it near South Broadway and Nagel Avenue in St. Louis.
The podcast’s account describes the discovery of shotgun pieces inside a concrete-filled planter near South Broadway.
The descriptions consistently identify concrete as the material used to conceal the weapon, though they differ in detail about the recovery.
The effort to hide the firearm was particularly unusual.
A weapon concealed inside hardened concrete would not be readily visible to someone passing the location.
Recovering such evidence could require investigators to identify the correct location and examine the material concealing the object.
The discovery became a key part of the investigation, as Biondolino described.
It also showed the importance of following leads that might initially seem improbable.
A planter filled with concrete would not ordinarily attract attention as a potential source of homicide evidence.
Yet the investigation led detectives to material associated with the murder weapon.
The available published sources do not provide a complete forensic account of the recovered shotgun components or establish the precise role each component played in the subsequent prosecution.
Those limitations are important.
The discovery is documented, but its significance should not be overstated beyond what the available reporting supports.
Peter Chafin and the Murder of Dominic Smith
The investigation eventually focused on Peter Chafin, a Florissant man and Smith’s neighbor.
According to KMOV, Chafin was prosecuted in connection with Smith’s September 2015 killing.
The case involved allegations that Chafin had shot Smith, concealed his body, disposed of the remains in the Mississippi River, and hidden the shotgun in concrete.
The prosecution would eventually proceed to trial.
However, the initial trial did not result in a conviction.
In 2022, jurors considering the first-degree murder and armed criminal action charges were unable to reach a unanimous verdict.
The deadlock prevented the trial from producing a final verdict on those charges.
During the proceedings, Chafin testified that he had not wanted to kill Smith but believed Smith represented a threat to him and his family.
A prosecutor characterized Chafin’s actions as vigilantism.
Those statements reflected positions presented during the criminal proceedings.
They should not be confused with the jury’s findings.
The jury’s inability to reach agreement meant the case remained unresolved through that trial.
For the criminal justice system, the outcome demonstrated that identifying and prosecuting a suspect does not automatically result in a conviction.
The prosecution pursued a different resolution.
The May 2023 Guilty Plea
On May 2, 2023, Peter Chafin pleaded guilty to second-degree murder and armed criminal action in connection with Dominic Smith’s death.
Chafin, then 48, received a 20-year prison sentence under a plea agreement.
According to KMOV’s reporting, the sentencing judge stated that Chafin would receive credit for more than six years already served in custody.
The guilty plea brought a formal resolution to the prosecution nearly eight years after Smith was killed.
The difference between the original charges and the final conviction matters.
Chafin had initially faced prosecution for first-degree murder and armed criminal action, but the 2022 trial ended without a unanimous verdict.
The subsequent plea agreement resulted in a conviction for second-degree murder and armed criminal action.
The 20-year sentence reflected that agreement.
For those following the case, the plea concluded a lengthy legal process that had continued well beyond the original homicide investigation.
A Separate Murder Case
KMOV’s May 2023 report also noted that Chafin faced a separate murder prosecution in St. Louis County involving the December 2016 death of his wife, Kiera Chafin, who was 22 at the time.
Authorities had accused him of strangling her at their Florissant home.
At the time of that reporting, the separate case remained pending, with a trial scheduled for June 2023.
That information provides additional context for the criminal proceedings surrounding Chafin.
However, the sources used for this article have not established the status of the separate prosecution as of November 2026.
Without additional court documentation, it would be inaccurate to describe that separate case as having resulted in a conviction, acquittal, or dismissal.
The December 2016 confession described in the podcast is also not reproduced in full in the publicly available episode summary.
Consequently, the precise relationship between that confession and the separate prosecution should not be presented as independently established beyond the podcast’s description.
The Investigative Work Behind a Difficult Case
The Dominic Smith investigation illustrates several challenges homicide detectives face.
The first was the condition and location of the victim’s remains.
Smith’s body was recovered from the Mississippi River weeks after the killing, requiring investigators to reconstruct events that had occurred earlier.
The second was the complicated nature of the information detectives received.
The podcast describes numerous rumors, conflicting tips, and possible criminal associations that complicated the search for reliable evidence.
The third was the extended period before investigators received the breakthrough described in December 2016.
The fourth was the unusual concealment of the shotgun.
Together, these circumstances created an investigation that required detectives to examine information from multiple directions.
The case also demonstrates why investigators cannot always rely on an immediate breakthrough.
Sometimes the information needed to advance an investigation emerges months or years later.
In Smith’s case, the podcast identifies a development in another murder investigation as the turning point.
That detail matters because it shows how criminal investigations can intersect.
Information obtained in one case may become relevant to another, even when the connection was not initially apparent.
The Importance of Separating Fact From Rumor
One of the most significant themes in Biondolino’s account is the difficulty of separating reliable evidence from unsupported information.
Homicide detectives frequently encounter individuals who claim knowledge of a crime.
Not every statement can be accepted at face value.
Investigators must consider whether a person has firsthand knowledge, whether the account is consistent with established facts, and whether independent evidence supports the information.
That process can be especially difficult when a case involves people with criminal histories, personal disputes, or suspected gang associations.
A reputation for criminal activity is not evidence of responsibility for a particular murder.
Similarly, an accusation from one individual does not automatically establish another person’s guilt.
The Smith investigation underscores the importance of maintaining those distinctions.
According to the podcast, detectives encountered numerous leads before receiving information that helped identify the killer.
The eventual conviction did not eliminate the need to evaluate the evidence carefully throughout the investigation.
Instead, it showed the importance of pursuing a case through a process that can produce a legally recognized outcome.
Why Older Homicide Investigations Matter
Although the Smith case eventually resulted in a conviction, its history offers a broader lesson about unresolved homicides.
An investigation does not necessarily end when the first wave of leads fails to identify a suspect.
Cases may remain open while detectives wait for additional information, forensic developments, or witnesses willing to provide new accounts.
Preserving investigative records can become especially important.
Reports, witness statements, evidence inventories, and investigative notes may provide context when new information emerges.
Comparing newly obtained information with earlier findings can help investigators recognize connections that were previously unavailable.
In the Smith investigation, the breakthrough reportedly came from a different murder inquiry rather than a newly discovered witness directly associated with the original recovery of the body.
That development illustrates why communication and information sharing can matter across investigative assignments.
A lead in one case may matter in another.
The Human Cost Behind the Investigation
While the concealed shotgun is one of the most memorable details of this case, the central story remains the murder of Dominic Smith.
Smith was 36 years old when his life ended in September 2015.
His body was concealed and discarded in the Mississippi River, where it remained until its discovery weeks later.
The circumstances surrounding his death became the subject of an extended investigation and prosecution.
For victims’ families, the passage of time between a homicide and a legal resolution can be substantial.
An arrest does not necessarily bring immediate closure, and criminal proceedings can continue through trials, motions, and plea negotiations.
The Smith case took nearly eight years to reach the May 2023 guilty plea.
Although the public reporting establishes the legal outcome, it does not fully document the personal experiences of Smith’s surviving relatives.
Those experiences should not be assumed or described without direct reporting.
What is established is that Smith’s death led to a criminal investigation that ultimately resulted in a conviction and prison sentence.
The Brighter Side of Blue Revisits the Case
The October 27, 2026, episode of The Brighter Side of Blue Podcast revisits the investigation through the perspective of former SLMPD homicide detective Mark Biondolino.
The episode runs approximately one hour and 45 minutes, with the featured interview beginning around the 39-minute mark.
Biondolino discusses the investigation he conducted with Detective Mike Herzberg, including the challenges of conflicting leads and the unexpected information that changed the case.
The episode also explores the discovery of shotgun components hidden in a concrete-filled planter.
For listeners interested in law enforcement, criminal investigations, and St. Louis history, the case offers an example of the complex work homicide detectives do.
The story also highlights a key distinction between identifying a suspect, building a criminal case, and securing a conviction.
Those stages can involve different challenges and may unfold over many years.
A Murder Case That Took Years to Resolve
The murder of Dominic Smith began as an investigation into a body recovered from the Mississippi River.
Detectives pursued leads involving conflicting accounts and suspected criminal connections.
An unexpected development in December 2016 reportedly helped identify the killer.
The investigation also uncovered the extraordinary concealment of shotgun components in concrete near South Broadway.
The criminal case proceeded through a 2022 trial that ended with a deadlocked jury before reaching a final resolution through Chafin’s May 2023 guilty plea.
Each stage demonstrates a different part of the investigative and judicial process.
The case did not produce an immediate conviction, nor did its resolution depend solely on discovering a concealed weapon.
Instead, it involved a complicated investigation followed by years of criminal proceedings.
For The Brighter Side of Blue, the story offers a meaningful look at the work detectives do when investigating violent crime.
It demonstrates the importance of following evidence rather than speculation, recognizing connections between investigations, and understanding that the path from a homicide to a conviction may be long and unpredictable.
Above all, the case is a reminder that behind every homicide investigation is a victim whose death demands answers.
For Dominic Smith, those answers eventually became part of a criminal conviction nearly eight years after his murder.
Listen to The Brighter Side of Blue Podcast
Episode: The Murder of Dominic Smith: A Cold Case and a Concrete Clue
Published: October 27, 2026
Featured guest: Former SLMPD Homicide Detective Mark Biondolino
Investigative partner: Detective Mike Herzberg
Episode length: Approximately 1 hour and 45 minutes
Featured interview begins: 39:26
Recording Studio: Columbo’s Cafe & Tavern in Dogtown
Business Profile Page on STL.News: https://www.stl.news/business-profile-the-brighter-side-of-blue/
Listen on Apple Podcasts:
Sources
1. The Brighter Side of Blue Podcast
“The Murder of Dominic Smith: A Cold Case and a Concrete Clue,” October 27, 2026.
2. KMOV / First Alert 4
“Florissant man accused of 2015 murder of neighbor gets 20-year term in plea deal,” by Kalie Strain, May 2, 2023.
Editorial Disclaimer
This article is based on published reporting and the publicly available description of The Brighter Side of Blue Podcast episode. The article is not a verbatim transcript of the podcast interview. The article distinguishes investigative details attributed to the podcast from independently reported court outcomes.
Peter Chafin pleaded guilty to second-degree murder and armed criminal action in Dominic Smith’s death in May 2023. References to other criminal allegations, suspected gang connections, or individuals discussed during the investigation do not establish guilt in unrelated matters. Individuals accused of separate crimes are presumed innocent unless and until proven guilty.
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