(CNN) -- Bill Cosby's defense lawyer says he is concerned about the entertainer's health following what he described as an "unfair" aggravated indecent assault trial that ended in a mistrial Saturday.
Prosecutors said Cosby, 79, drugged and sexually assaulted Andrea Constand, the former director of operations for Temple University's women's basketball team, at his home near Philadelphia in January 2004. Cosby pleaded not guilty to the charges.
After more than six days of deliberation in Norristown, Pennsylvania, jurors were unable to come to a unanimous decision beyond a reasonable doubt.
In an exclusive interview with CNN's Jean Casarez, attorney Brian McMonagle said the jury's inability to reach a verdict made it clear the trial should end.
"It became a great concern of mine that these people had deliberated longer than the case has tried. Once a jury decides deadlock, what is the point to keep going?" McMonagle said.
Constand first told police about the alleged assault in January 2005, a year after she says it took place. The district attorney at the time declined to press charges, citing insufficient evidence. She sued Cosby in a civil suit and settled for an undisclosed amount in 2006.
In late 2014, dozens of women went public with accusations that Cosby drugged and sexually assaulted them over the course of his lengthy comedic career and in July 2015, a judge unsealed Cosby's deposition in that 2006 civil lawsuit. Cosby's admissions in that deposition led Montgomery County prosecutors to file charges against him.
'Waiting so long, it's wrong'
McMonagle said he had always felt that this year's trial was unfair.
"Imagine it's you being asked to defend age-old accusations -- what do you do to defend that? Cosby is fortunate he has the money to get a proper defense," he said. "Waiting so long, it's wrong. Witnesses have died. We have run into walls trying to get records. We were fortunate that the 2005 investigation was so extensive."
McMonagle said asking Cosby to surrender had been difficult.
"(It was) hard on him. He had to be awakened from his home -- he is blind -- he had to be taken away. I've handled a lot of cases but I wasn't quite prepared for what I was going to see."
Cosby -- who is legally blind and carries a cane -- then had to endure a taxing trial, the attorney said.
"I have been greatly concerned for his health, I don't know if I can survive what he survived this week. This was difficult for me, and I don't know how he could sit in that room and endure what he did. He sat for 12 hours a day, he went without sleep for most of this trial -- I have no doubt it took a big toll on him."
But the entertainer had kept positive, McMonagle said: "... some of the most aggravating parts of our trial he kept us going, telling jokes, cracking a smile."
McMonagle said he respected Cosby's efforts to keep his family out of the courtroom spotlight.
"I see people using family as shields, he refused to do that, he refused to expose his family to circus-type atmosphere -- he was not going to use his family as a shield and I respect him for that. This was about him and he was not going to allow them to be shields."
Cosby had previously admitted to having an affair, McMonagle said, but that was not what he had been on trial for.
"As I said before, about the carrying-ons, I said 'listen, we don't run from the fact that this is a man who danced outside his marriage'."
After the judge declared a mistrial Saturday, prosecutors immediately announced they would retry the case. The judge said he would try to schedule a new trial within 120 days.
McMonagle said it was up to Cosby whether he would represent him in court again.
"If he wants me to go to battle for him again, I will."
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