(CBS News) BOSTON -- The showdown everyone was waiting for took place Thursday at the trial of former mob boss James "Whitey" Bulger, when one of his top lieutenants testified against him. But that was overshadowed by the death of a potential witness. The body of 59-year-old Stephen Rakes was found in a Boston suburb on Wednesday afternoon. Rakes had been eager to testify against Bulger, but was removed from the prosecution's witness list just one day before his body was discovered.
An autopsy is being conducted, and while the district attorney's office says there were no obvious signs of trauma, the police are treating his death as suspicious and say Rakes' vehicle is missing.
Rakes had owned a liquor store in south Boston in the 1980s. He claimed Bulger and his partner Steven Flemmi forced him to sell them his store at gunpoint. He described the alleged incident in an interview with CBS affiliate WBZ last year.
"Flemmi put the gun on the table, and then they picked up one of my children and said, you know, 'It would be a sin - would be a sin to see this child grow up without a father,'" Rakes recounted. "It was a bad day. I melted -- I didn't know what to do."
The 79-year-old Flemmi, who's serving a life sentence for 10 murders, was Thursday's star witness. It was the first time in nearly 20 years that he had come face to face with Bulger.
On the witness stand, Flemmi described his relationship with Bulger as "strictly criminal" and characterized the former crime boss as "overbearing" and "forceful." He also said Bulger was an informant for the FBI, something Bulger, through his lawyers, sharply denies.
After Flemmi's testimony, the former partners in crime glared at each other and exchanged heated words.
Boston Globe columnist Kevin Cullen, who has been covering the trial from the start, said Flemmi's testimony was the ultimate betrayal.
"In their world, you don't rat out your friends," Cullen said. "You could see the tension, the body language -- they hate each other."
Flemmi is set to resume his testimony Friday. He's expected to describe how Bulger strangled two women in the 1980s. Bulger has vehemently denied that he killed any women through his lawyers.