Boston Bomb Suspect Eyed in Connection to 2011 Triple Murder

In the wake of the revelations about the violent nature of accused marathon bomber Tamerlan Tsarnaev, investigators in the Boston suburbs tell ABC News they are probing whether he may have been involved in an unsolved grisly triple homicide of a former roommate and two others. The murders took place around the tenth anniversary of the September 11 attacks.

The victims were found in a Waltham, Massachusetts apartment. They had their throat slashed, their heads nearly decapitated. Their mutilated bodies were left covered with marijuana.

It was a gruesome scene – but also perplexing to law enforcement. While drugs appeared to factor into the motive, the murderer left both the marijuana and thousands of dollars in cash behind in the Waltham apartment. While the investigation has been active for more than a year, authorities acknowledged they have had few leads.

Two law enforcement sources told ABC News that may now change, with the bomb attack prompting a fresh look into Tsarnaev's alleged penchant for violence.

Even before the bombing, police records show, there was an indication of a rage growing inside of Tsarnaev. Court documents obtained by ABC News show in July 2009 he was arrested for domestic violence after his then-girlfriend made a frantic 911 to report she was "being beat up by her boyfriend." The police report, which was redacted to hide the girlfriend's name, says that Tsarnaev admitted to responding officers that he slapped her. The case was later dismissed.

ABC News