(CNN) — A missing persons case has turned into a homicide investigation after four dismembered bodies found in an Oklahoma river were identified as those of four men who went missing last week, police said.
“I have worked on more than 80 murders in my career. I’ve worked murders with multiple victims. I’ve worked on dismemberments, but this case involves the largest number of victims and is a very violent event,” Okmulgee, Oklahoma Police Chief Joe Prentice said Monday.
The four men: Mark Chastain, 32; Billy Chastain, 30; Mike Sparks, 32, and Alex Stevens, 29, were reported missing by relatives last Monday night or early Tuesday, after biking out of Billy Chastain’s Okmulgee home around 9:00. pm on Oct. 9, police said.
The discovery of their dismembered bodies in the river days later widened the investigation and raised new questions, the chief said. This is what we know about the case:
All the men found in the river had been shot
On Oct. 14, a passerby called police after seeing something suspicious in a river outside Okmulgee, a city of about 11,000 people about a 35-mile drive south of Tulsa, Prentice previously said.
The police arrived and saw wreckage sticking out of the river, and ended up finding several bodies.
On Monday, the chief announced that the bodies were identified as the four missing men, all of them shot and dismembered.
“Although the official cause and manner of death are still pending, each victim sustained gunshot wounds,” Prentice said. “The four bodies were dismembered before being placed in the river and that is what caused difficulty in determining the identities.”
The remains were recovered over several days and it is unclear what kind of evidence investigators will be able to recover, given that the bodies were in the water.
“Whenever there is water involved, it is much more difficult to identify evidence,” the chief said.
Police have not recovered any bicycles, nor the weapon used in the murders.
Police believe the 4 men were planning a crime
While it’s unclear exactly what led to the four men’s deaths, Prentice said the preliminary investigation appears to show the men were planning to commit a crime when they left Chastain’s home.
The chief told a news conference Monday that the assumption is based on “information provided by a witness who reports that they were invited to go with the men to quote in quotes ‘take a bite big enough for all of them.'”
“That’s common terminology for engaging in some type of criminal behavior, but we don’t know what they were planning or where they were planning to do it,” Prentice added.
After the men were reported missing, police tracked two of their cellphones and discovered they went to two junkyards: one about 5 miles from the river and the other about 10 to 12 miles from the river, Prentice told CNN. Saturday.
Police later found “evidence of a violent event” on property adjoining one of those locations, the chief said, without elaborating on the findings.
Missing a ‘person of interest’
Police have identified a person of interest in the case, but no charges have been filed, the chief said Monday.
Prentice said the person is not a suspect, but “a person of interest that we would like to speak with.” That person has denied knowing the four men, the chief added.
The person has been missing since Saturday night and may be suicidal, Prentice said.
Now that the investigation is a homicide investigation, Prentice said, the department will be a little more strict about additional procedures “to protect the integrity of the investigation.”
CNN’s Michelle Watson and Melissa Alonso contributed to this report.