A man who was suffocated and found floating in the Patapsco River this week had been abducted and held for ransom and is believed to be connected to a violent drug gang whose feuding with rivals may have been responsible for at least five homicides last summer, according to law enforcement sources and court records.

Authorities are monitoring the situation and exploring leads as it remains unclear whether the killing of Eric Pendergrass, 26, is an isolated incident or related to the spate of retaliatory violence associated with the April kidnapping of the teenage brothers Stephon and Sterling Blackwell.Sources with knowledge of the investigation of Pendergrass' death who did not want to be identified because of the sensitive nature of the case said the victim was an emerging, midlevel drug dealer with connections to the Blackwell family, who operated on the city's east side.

Federal prosecutors charged a person of interest in the case this week with possession of ammunition by a convicted felon as officials continue to probe Pendergrass' disappearance.

According to an affidavit filed in U.S. District Court, Pendergrass' attorney, Christie Needleman, contacted city homicide detectives Feb. 1 and said that Pendergrass' girlfriend reported that he had been abducted. The girlfriend told police that she received a phone call at 1:30 a.m. that day in which Pendergrass told her to retrieve a plastic bag from a closet in her home and to give it to a woman named "Darlene."

"Pendergrass explained that this needed to be done quickly and then hung up," Detective Brian Lewis wrote in the affidavit, which was first posted on the City Paper's Web site. "[The girlfriend] described Pendergrass as abrupt and appeared under duress. ... Pendergrass pleaded with her to do as he requested and hung up the phone."

The girlfriend was asked to deliver the "large sum of banded-like bank money" to Pendergrass' mother's home, in Northwest Baltimore, near Pimlico. Outside the home, a woman who identified herself as "Darlene" and holding a cell phone tightly to her ear, took the money and climbed into a silver-colored Cadillac STS.

Witnesses recorded the license plate number, and police discovered that the vehicle was registered to Darryl Nichols, 33. Lewis found the vehicle and Nichols in the 1600 block of Northwick Road and took him to the police's homicide division for questioning.

Police executed a search warrant on Nichols' home and recovered $2,000 in banded U.S. currency, a plastic bag containing 500 rounds of .22-caliber Remington Thunderbolt ammunition and five loose rounds of Winchester .38-caliber ammunition.

Pendergrass was awaiting an April trial in Baltimore Circuit Court on seven counts of handgun and drug possession and traffic charges. Records show he was on probation through December for a May drug conviction in which his entire six-months prison sentence was suspended. He was also convicted in 2003 on a handgun charge.

Pendergrass' family members reached at his mother's house declined to comment.

The April kidnapping of the Blackwell brothers from a Catonsville home set off a regionwide search, including Amber alerts and efforts by multiple police agencies. Police reported that six masked gunmen had burst into the house and held 10 people hostage for eight hours before stealing a car and leaving with the two teen boys in an abduction they said appeared to be connected to Baltimore's heroin trade.

Four days later, a relative brought the boys to the Towson police headquarters, but the Blackwells wouldn't say where they had been, who had taken them or what had happened while they were missing. Other leads in the case dried up.

But over the next three months, as many as five people were killed in Baltimore in homicides police believed were connected to the Blackwells' kidnapping, several law enforcement sources told The Baltimore Sun last year.

In a span of one week, three people police believe were connected to the case were killed in Baltimore in brazen daytime shootings. It was not clear whether the kidnappings triggered the violence or if that act was itself part of a rivalry, police sources said at the time.

Police fanned out throughout the city to find associates of the groups, and tensions apparently eased and violence has been muted, officials say. Now, however, police are on heightened alert again, for fear that Pendergrass' abduction and murder could lead to a new cycle of retaliation.