By Scott Malone

BOSTON (Reuters) - An attorney for ex-New England Patriots star Aaron Hernandez claimed on Wednesday that a key witness who prosecutors say will finger the convicted killer as the gunman in a 2012 double murder is blaming his former friend to hide his own guilt.

The 27-year-old former professional football player is charged with gunning down two immigrants from Cape Verde, an attack that prosecutors contend was motivated by Hernandez's anger after one of the men accidentally spilled a drink on him at a Boston nightclub.

But defense attorney Jose Baez told jurors there was no forensic or video evidence that Hernandez had an altercation with the two men and claimed that Hernandez's former friend, Alexander Bradley, had instead targeted them over a drug-related dispute.

"Sometimes you want something so bad that you are willing to make a deal with the devil to make it happen. That is exactly what the Commonwealth (of Massachusetts) did in this case, which is make a deal with the killer of Daniel Abreu and Safiro Furtado, who is Alexander Bradley," Baez said on the first day of the second murder trial Hernandez has faced in two years.

Prosecutors say that Bradley was driving the car from which Hernandez shot the two men and will identify him as their killer.

Bradley could not be reached for comment on Wednesday.

Hernandez is already serving a life sentence after being convicted of murdering an acquaintance near his home in North Attleborough, Massachusetts, in 2013.

Prosecutors contended that Hernandez and Bradley followed the men when they left the nightclub, after Hernandez spent several hours stewing about the spilled drink. Assistant District Attorney Patrick Haggan said that Hernandez had often told friends he felt disrespected while partying at Boston nightclubs.

Bradley argued that he should ignore the incident given his fame, Haggan said.

"The seeds of this murder were planted months, if not a year, before," Haggan said. "In the months before, there would be multiple times the defendant would express the fact that he felt tried, he felt tested, he felt disrespected, he felt threatened while he was out."

Hernandez is also charged with witness intimidation for shooting Bradley in the face on a 2013 trip to Florida, after his friend brought up the murders.

Hernandez had a $41 million contract when he was arrested in June 2013 and charged with murdering Odin Lloyd, an acquaintance. The team dropped him within hours of his arrest.

(Editing by Matthew Lewis and Jonathan Oatis)