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(CNN) -- Casey Anthony's car reeked of what they deemed the unmistakable odor of a decomposing body, her father and a tow company manager testified Friday in the Orlando woman's capital murder trial.
The odor was so powerful, George Anthony said he could not drive it home from the impound lot where it had been towed two weeks before without rolling down the windows, he said.
"I did worry for my daughter and granddaughter," George Anthony testified, noting that he had not seen Casey or her 2-year-old daughter Caylee since June 24. "I didn't want to believe what I was smelling."
The defense pointed out -- and George Anthony admitted -- that he did not call police after noticing the smell, nor did he tell authorities about his concerns. Later that day, his wife Cindy did call 911, sparking the investigation that led to the discovery months later of Caylee's remains and the arrest of her mother for the toddler's murder.
"Looking back, sir, there's a lot of things I wish I would have done," George Anthony said, after being pressed by defense attorney Jose Baez as to why he didn't contact police immediately.
Anthony's white Pontiac Sunfire took center stage in the fourth day of Anthony's capital murder trial.
Anthony, 25, is charged with seven counts, including first degree murder, aggravated child abuse and misleading police in the death of her daughter, whose remains were discovered in December 2008.
Prosecutors say Anthony used chloroform on her daughter and then put duct tape over her nose and mouth, suffocating the girl.
Anthony's attorneys argue that she did not kill Caylee, but rather that the girl accidentally drowned in the Anthonys' pool on June 16. They say she and her father, George Anthony, panicked and kept the death a secret. George Anthony denied that claim in testimony Thursday.
Anthony's car was found, apparently abandoned, in a financial-services company parking lot on June 24.
It was towed by a wrecker service to an impound lot on June 30 and remained there for about two weeks, the wrecker service's operations manager, Simon Birch, told jurors.
Closed up, the car gave off the faint smell of human decomposition, Birch testified.
"It's a very, very unique and distinctive smell," Birch said, noting that he has had the misfortune of coming into contact with decomposition in cars numerous times.
Birch said the smell became more noticeable after George Anthony and his wife arrived to pick up the car and they opened first the door and then the trunk.
George Anthony recalled his mind racing with concern for his daughter, whom he had believed was in Jacksonville, Florida, with the car, and his granddaughter, whom he had not seen in nearly a month.
"Please God," he recalled thinking as he prepared to open the trunk, "don't let this be Casey or Caylee."
The smell did not seem to dissipate after they removed a lightly-filed garbage bag from the trunk, Birch said.
But after being called back to the stand later Friday, George Anthony said he did not notice the stench was stronger after he opened the trunk and removed garbage from the trunk.
In response to a question from Baez implying he was somehow trying to distance himself from evidence in a potential crime, George Anthony said, "I would not have walked away ... from something. That's not in my make-up. ... I believe I'm a pretty good guy."
Before challenging George Anthony, Baez questioned why Birch never called police, even after learning the car had been towed by authorities for forensic analysis.
"I had no idea why it was towed to forensics," Birch said.
William Waters, a friend of Anthony's who testified that he went shopping with her on July 5, testified that she had a friend's car at the time. He said she explained that she did not have her own because it needed an alignment or a tune-up.
The car also figured in testimony Thursday, when George Anthony testified about an argument he had with his daughter over two missing gas cans from the storage shed at his house.
On June 24, George Anthony called police to report the break-in and report the gas cans missing. He testified that he saw his daughter later in the day and argued with her about the missing cans. He had a hunch she had them, he testified, as she had taken them before.
George Anthony said that when he went to get them out of his daughter's car, she bristled, brushed past him, quickly opened the trunk and retrieved the gas cans. Then she threw them down and told him, "Here's your f---ing gas cans."
The cans are significant because duct tape on them appears to be the same as that found on the mouth of Caylee's skeletal remains, which were found six months after the child went missing. The type of tape, prosecutor Linda Drane Burdick told jurors in her opening statement this week, is relatively rare.
George Anthony said that when his daughter returned the gas cans to him, there was no tape on them. He said he had put the tape on to replace a missing vent cap.
In earlier testimony, prosecutors displayed evidence and questioned witnesses suggesting that Casey Anthony seemed unburdened in the days after her daughter disappeared -- attending a party and going shopping for furniture, clothes and beer.
Jurors saw silent surveillance videos of Anthony shopping at Target, Ikea and other stores in the days following her daughter's disappearance.
The videos were shown over the objection of defense attorneys, who said they were irrelevant to the charges against Anthony and could improperly impeach her character and state of mind in the eyes of the jury.
They also heard Waters testify that Anthony attended an Independence Day party at his house on July 4, 2008 -- about two weeks after Caylee was last seen -- and that the two also went shopping the next day. She gave no indication that anything was wrong either time and only briefly mentioned her daughter, Waters testified.
Waters' testimony was similar to statements Thursday from numerous witnesses who said Anthony did not mention her daughter's disappearance until her mother, Cindy Anthony, reported the girl's absence to police on July 15.
Among the witnesses was a former boyfriend, Ricardo Morales, who said Anthony was "happy, smiling" during his encounters with her in July.
Another friend, Matthew Crisp, testified that he met Anthony for lunch on July 7 and asked about Caylee. Anthony told him the girl was "on a play date with one of her girlfriends who also had a child."
Another former boyfriend, Anthony Lazzaro, and his roommates said that when they asked where Caylee was, Anthony told them she was with her nanny, mentioning that the nanny was taking her to Universal Studios and to the beach.
In the early days of the investigation, Anthony said the nanny, who she said was named Zenaida Gonzalez and nicknamed "Zanny," had kidnapped Caylee. Authorities were never able to find the nanny but did track down a woman with that name who denied knowing Anthony and sued her for defamation.
Anthony also repeatedly visited at least two nightclubs during the month Caylee was missing, once participating in a "hot body" contest.
Defense attorneys explain Anthony's behavior as a result of what they allege was sexual abuse by her father beginning as a child. Anthony was schooled from a young age to "hide her pain," her attorneys argue. In testimony, George Anthony has denied sexually abusing his daughter.
In cross-examination by lead defense attorney Jose Baez, those who saw Anthony and her daughter together testified that Caylee was well taken care of and that Anthony, at least to their knowledge, appeared to be a good mother.
In a dramatic moment Friday morning, the fiancee of Casey Anthony's brother broke down when asked to describe Anthony's relationship with her daughter.
The fiance, Mallory Parker, described the relationship as "amazing."
"Casey and Caylee had a very special bond," Parker, a witness for the prosecution, said with a quivering voice while under cross-examination by Anthony's lead attorney, Jose Baez.
Anthony appeared to cry as Parker spoke.
In all, Anthony is charged with first degree murder, aggravated child abuse, aggravated manslaughter of a child and four counts of misleading police. If she is convicted of capital murder, she could be sentenced to death by the seven-woman, five-man jury.
The trial, now in its fourth day, is expected to last six to eight weeks.
CNN's Ashley Hayes contributed to this article
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