A jury last week found the former "Baretta" star not guilty in the 2001 slaying of his wife, Bonny Lee Bakley, who was shot in a car outside a restaurant where the couple had dined.
"Quite frankly, based on my review of the evidence, he is as guilty as sin. He is a miserable human being," Cooley said Wednesday.
Blake's attorney, M. Gerald Schwartzbach, said the district attorney's attack on the jurors is inappropriate and "small-minded."
Juror Chuck Safko said: "To hear him say we aren't a smart jury is sour grapes. They didn't have a good case. Their case was built around witnesses who weren't truthful."
Blake jury foreman Thomas Nicholson says he was "disgusted" by Cooley's remarks.
Cooley is not backing down, despite the criticism from other lawyers as well as a demand by the jury for an apology.
"There was a failure," said Cooley Thursday night, saying it wasn't on the part of the prosecution or the LAPD. "The jurors didn't quite get it."
"It was harsh. It was blunt, and I could have phrased it differently, but bottom line it was the wrong verdict," said Cooley, speaking at an event sponsored by the University of California's La Raza Law Student Association.
The jury of seven men and five women delivered the verdicts on its ninth day of deliberations, following a trial with a cast a characters that included two Hollywood stuntmen who said Blake tried to get them to bump off his wife.
However, no eyewitnesses, blood or DNA evidence linked Blake to the crime. The murder weapon, found in a trash bin, could not be traced to Blake, and witnesses said the minuscule amounts of gunshot residue found on Blake's hands could have come from a different gun he said he carried for protection.
"They couldn't put the gun in his hand," jury foreman Thomas Nicholson told reporters after the verdict, adding that the evidence could "never connect all the links in the chain."
Laurie Levenson, a professor of criminal law at Loyola Law School in Los Angeles, said Cooley's words are unprofessional.
"I think you have to give the jury credit. They are a very conscientious jury. It was a reasonable-doubt case, and disagreeing with Mr. Cooley doesn't make them stupid," said Levenson, in an interview with the Los Angeles Times.
"He was acquitted because two key prosecution witnesses against him were not credible enough to convince jurors that Blake was actively seeking to murder his wife. He was acquitted because theand because the eyewitness testimony was ambiguous, at best," said CBS News Legal Analyst Andrew Cohen.
Blake was charged with shooting Bakley, 44, in their car outside the actor's favorite Italian restaurant on May 4, 2001, less than six months after their marriage. He would have faced life in prison since prosecutors did not seek the death penalty.
The four-month trial was part of a wave of celebrity court cases in California that have provided endless fodder for the tabloids and cable networks. The Michael Jackson child molestation trial was starting just as the Blake case was wrapping up, and rock 'n' roll producer Phil Spector will stand trial later this year in Los Angeles for allegedly murdering a B-movie actress.
Blake has been in front of the camera since pre-school days, when he played Mickey in the "Our Gang" movie series. He was nominated for an Oscar for the 1967 movie "In Cold Blood," in which he portrayed a killer who dies on the gallows.
In "Baretta," Blake played a tough-talking, street-smart detective whose catchphrase was "Don't do the crime if you can't do the time."