Branton died of natural causes on April 19 in Los Angeles, his son, Tony Nicholas, told the Los Angeles Times ( http://lat.ms/15L6WFQ).
Branton, the only 1948 black graduate of the Northwestern University law school, already had decades of civil rights law when he became co-lead defense counsel at Davis' trial.
Davis gained national attention in 1969 when the University of California, Los Angeles professor was fired for being a member of the Communist party.
The next year, she was charged in a 1970 armed takeover of a Marin County courtroom. A 17-year-old boy smuggled guns into the San Rafael courtroom and armed three black convicts. They tried to drive away with a judge, prosecutor and three women jurors as hostages. Police opened fire and in the melee the judge, the teenager and two of the convicts died.
Davis was charged with murder, kidnapping and criminal conspiracy because she had bought the smuggled guns—including a shotgun that had been taped to the judge during the escape attempt.
She fled and was placed on the FBI's 10 most wanted list.
After her arrest, the case became a cause celebre among progressives. She claimed the guns had been stolen from her, and eventually was acquitted by an all-white jury.
Branton was instrumental in the decision, Davis told the Times on Thursday.
On the trial's closing day, he showed the jury a drawing of his client wrapped in chains, then ripped it away to reveal another of Davis unbound and urged jurors to "pull away these chains as I have pulled away that piece of paper." He then attacked the prosecution case and asked jurors to "understand what it means to be black."
"Certainly his brilliant closing argument had a profound impact on the jury," Davis said.
Branton had been involved in civil rights cases dating to the late 1940s. He helped singer Nat King Cole integrate the wealthy Los Angeles neighborhood of Hancock Park, defended Communists in the McCarthy era and won police misconduct cases decades before Rodney King.
"He was a hero of mine," said Connie Rice, a Los Angeles civil rights attorney who helped lead efforts to reform the LAPD after the King beating.
"All the things I've done, Leo Branton did 50 years before I even thought about going to law school," she told the Times. "He saw himself not as a private practitioner out to make money for himself but as a lawyer with the skills to be a champion for black liberation."
Branton also was an entertainment lawyer who represented the Platters, Miles Davis and Richard Pryor.
Branton practiced law until early this year, and won his last case involving a dispute with a credit card company, his son said.
In addition to Tony, Branton is survived by two other sons, Leo Branton and Paul Nicholas, a brother, sister and five grandchildren.
Information from: Los Angeles Times, http://www.latimes.com