Aaron Hernandez Update: Prosecutors making case against ex-NFL star in 2012 double-homicide, report says

(CBS) BOSTON - Prosecutors have begun making the case to a grand jury that former NFL star Aaron Hernandez should be charged in a 2012 double-homicide in Boston's south end, two law enforcement officials briefed on the investigation reportedly told the Boston Globe.

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"The case against Hernandez appears to be strengthening," one of the officials told the paper on the condition of anonymity.

Hernandez, 23, is already facing murder charges in the June 17 death of 27-year-old Boston semi-pro football player Odin Lloyd. He has pleaded not guilty and is being held without bail.

READ: Timeline of Aaron Hernandez murder investigation

Sources tell CBS Boston that Lloyd, of Dorchester, Mass., may have been executed because he had information about Hernandez's possible involvement in the double-homicide.

Following Hernandez's arrest last month, reports began to surface linking the former New England Patriots tight-end to the 2012 double-murder. While sources confirmed to CBS Boston that Hernandez was being looked at in connection with the crime, Boston Police Chief Ed Davis would only say the double-murder investigation had some new life.

Safiro Furtado, 28, and Daniel Abreu, 29, both of Dorchester, were gunned down July 15, 2012 as they sat at a traffic light in Boston's South End. A silver SUV with Rhode Island plates was reportedly seen speeding away from the drive-by shooting. No arrests have been made in the case.

On June 28, a silver SUV reportedly matching the description of the car Boston police had been looking for in connection with the double-homicide was towedfrom Hernandez's uncle's home in Bristol, Conn. at the request of police.

The motive behind the killings of Furtado and Abreu, friends who worked for a cleaning company, remains unknown, the Boston Globe reports. Their relatives have reportedly said the men did not know Hernandez and neither man had a criminal record.

One of the officials with knowledge of the double-murder investigation told the paper that investigators are not in a hurry to charge Hernandez with the 2012 killings because he is already being held in jail without bail.

In Massachusetts, anyone charged with murder must be indicted by a grand jury before they can proceed to trial.

Hernandez is scheduled to appear in court Wednesday for a probable cause hearing in the death of Lloyd. His lawyers say the case against him is circumstantial and he wants to clear his name.

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