Authorities in Suffolk County, Massachusetts, announced Wednesday that they want to speak to several of former NFL player Aaron Hernandez's tattoo artists. 

Authorities are investigating every angle in the multiple murder cases against the former New England Patriot, CBS Sports reported. 

Investigators said in a statement that they believe the tattoo artists "may have made observations of evidentiary value in the pending Suffolk County murder prosecutions."

Hernandez was indicted on a double murder charge on May 15. He is charged with the deaths of Daniel Abreu and Safiro Furtado in a July 2012 drive-by shooting in Boston. 

Police said they want to speak with tattoo artists who worked on Hernandez's right forearm between February 2012 and June 2013. Hernandez is believed to have been in Bristol, Connecticut; Hermosa Beach, California; Palm Beach and Miami, Florida; and Massachusetts during that time period. 

Investigators said they are willing to speak to any tattoo artist who worked on Hernandez at any time and not just the ones who worked on him during that specific time frame. 

The weapon that was used in the double shooting was recovered in August 2013. Two months later, a man who survived the drive-by identified Hernandez as the person who fired the weapon. 

Relatives of Abreu and Furtado said neither of the victims knew Hernandez. Both of the victims worked for a cleaning company, and neither one had a criminal record. 

The shooting took place at a red light after the men had left the Cure Lounge, a club in Boston's south end. 

"They just came up and started firing for no reason at all," an eyewitness told Fox 25 last year. "We never had any trouble. We were not those kind of people. We were just having fun. ... Things happened so fast. I was trying to defend myself. They were shooting everywhere inside the car, front to back. They just came to kill. That's it."

The witness, who remains anonymous, said he recognized Hernandez's face when he was arrested last summer for Lloyd's murder. 

While the motive for the murders is unclear, if Hernandez is found guilty, it means that he played an entire season in the NFL after murdering two people. 

Hernandez is scheduled to be arraigned on May 28 for the double murder. 

He is also awaiting trail for the first-degree murder of Odin Lloyd. Hernandez allegedly picked up Lloyd from his apartment in Boston in a rental car shortly before Lloyd was found fatally shot on June 17. Lloyd was found dead in an industrial park near Hernandez's North Attleborough home. 

According to authorities, surveillance cameras show the rental car leaving the scene of the crime, and Hernandez carrying a gun when he returned to his home shortly after. 

He was also indicted a few weeks ago on charges related to a jailhouse fight, according to the district attorney's office in Massachusetts. 

A grand jury in Bristol County indicted Hernandez on charges of assault and battery stemming from the jailhouse altercation on Feb. 25, according to CNN. 

He was also indicted for threatening to do physical harm to someone who worked at the jail in November.