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(CNN) -- A dog trained to locate human remains alerted his handler to them in two locations: the trunk of Casey Anthony's car and a corner of her parents' back yard, the handler testified in Anthony's capital murder trial Tuesday.
On first pass by the dog, Gerus, around Anthony's white Pontiac Sunfire on July 17, 2008, "he started indicating in the rear of the vehicle," said Orange County, Florida, sheriff's Deputy Jason Forgey, a K-9 handler. "I could tell he was working something."
As the dog came around the front of the car, Forgey said he asked that the trunk be opened. When Gerus came around to the trunk, he put his front paws inside, then lay down -- a signal to Forgey that he had detected the scent of remains.
He said Gerus also alerted in the southeast corner of the Anthony back yard. However, during a cross-examination that grew testy at times, Forgey told defense attorney Jose Baez that after technicians had examined the area and scraped the surface of the land, he returned the following day and the dog did not alert in the back yard.
Casey Anthony, 25, faces seven counts in the death of her 2-year-old daughter, Caylee, including first-degree murder, aggravated child abuse and misleading investigators. If convicted, she could face the death penalty.
Members of Caylee's family reported they last saw her on June 16, 2008, but no one alerted police until July 15, when the girl's grandmother, Casey Anthony's mother, tracked Anthony down and demanded answers.
Prosecutors allege Anthony used chloroform on her daughter and suffocated her by putting duct tape over the little girl's mouth and nose. They allege Anthony put her daughter's body in her car trunk before disposing of it. Caylee's skeletal remains were found in December 2008, less than a mile from the home of Anthony's parents.
Anthony has pleaded not guilty and denied having anything to do with her daughter's death. Baez has said that when all the facts are known, it will become clear his client is innocent.
The Orlando woman's attorneys argue Caylee drowned in the family pool on June 16. They say Anthony and her father panicked and covered up the death. George Anthony denied the claim during his testimony.
Forgey testified that Gerus has had false alerts -- alerting when nothing was actually there -- but they are rare and occurred during training, at the end of a long day of working when the dog was most likely tired, not during his work on cases.
Baez pointed out that Gerus visited the scene where Caylee's remains were eventually found, tasked with looking for some small bones that were still missing. The dog did not find them, Forgey testified.
Baez attempted to show the dog did not alert at the scene where the remains were found at all, but Forgey said that wasn't true. "He was alerting and trying to get to where I already knew the target was," the location where the body was found, he said. "I wouldn't allow him to get to that because I'm looking for other items."
He said he knew the missing bones were not in the same area where the remains were located, as crime scene technicians had already thoroughly searched that spot.
He explained the conflicting results at the Anthony home by saying that he believed Gerus alerted to a scent on the surface of the land. Once technicians disturbed the surface, he said, the scent was diminished "where the dog wouldn't find it. It was gone at that point."
On cross-examination, however, he admitted he does not know the real reason behind the conflicting alerts. Still, he said, "in every single time he's had an alert besides this case, he's had a find," that is, he found remains.
Baez also took Forgey to task for not videotaping Gerus' searches related to the Anthony case. But Forgey told prosecutor Linda Drane Burdick he has gone on over 3,000 calls with police dogs and very few were videotaped.
A crime scene investigator, the operator of a towing company and members of Anthony's family all have testified they smelled a bad odor coming from Anthony's car after it was found abandoned in a parking lot on June 27, 2008, and then towed four days later.
A bag of trash found in the trunk, which had been sitting there for weeks during a Florida summer, has been suggested as a possible source of the odor. But Forgey told Burdick his dog does not alert on trash, and has been trained around garbage.
Forgey told Baez that he's smelled human remains on numerous occasions and "I smelled it clear as day" in Anthony's car.
He said that in 2006, Gerus was called out on six cadaver searches. In 2007, he conducted nine. In 2008, however, that number increased to 71, the result of tips in the Anthony case, Forgey testified.
Earlier testimony on Tuesday focused on the trunk of Anthony's car. Michael Rickenbach, an FBI forensic chemist examiner, testified that he analyzed pieces of the trunk liner, carpet and parts of the spare tire cover, among other items.
On those, he said, chloroform "residue" was found, but it was at low levels. But he did not want to offer specific levels, saying it would not be appropriate because he conducted qualitative testing, confirming chloroform's presence, rather than quantitative testing, which would detect its level.
Under questioning from prosecutor Jeff Ashton, Rickenbach said the samples were sent to him in a cardboard box, not a sealed container, which could have allowed some of the chloroform to evaporate, lowering the levels present. Having the car trunk open for a time might also lower the levels, he said.
On Monday, Arpad Vass, a senior research scientist at Tennessee's Oak Ridge National Laboratory, testified that the presence of chloroform on a carpet sample from the trunk was found at a "shockingly high" level -- far beyond what normally would be seen in environmental samples.
Both Vass and Rickenbach tested the carpet inside the trunk. However, Vass, who is not a chemist, was attempting to find compounds associated with human decomposition. Rickenbach was specifically testing for the presence of chloroform.
Earlier Tuesday, crime scene technician Gerardo Bloise testified about the bag of trash in the trunk. Asked what the trash smelled like, Bloise said it smelled like garbage. He told jurors it did not smell the same as the other odor in the trunk.
The trash bag held items including food wrappers, soft drink cans, pieces of an empty pizza box and napkins, Bloise testified. He said some of the items were wet when he received them and he put them in a "drying room" -- a common procedure for wet evidence.
On cross-examination, Baez alleged that drying the napkins and then putting them in a plastic bag rendered them useless for DNA testing. But Bloise insisted he was following proper protocol, saying he did not think after visually inspecting the napkins that DNA testing was necessary as he did not detect the presence of blood.
On Monday, Vass told jurors in the Orlando courtroom that the presence of a decomposing human body is the only plausible explanation for the odor in Anthony's trunk and the results found in forensic testing.
Testing was conducted on carpet samples from the trunk of the Pontiac Sunfire, along with a spare tire cover, scrapings from the wheel well, air samples and paper towels found in the trash bag that had been in the trunk, said Vass, who spent all day Monday on the stand.
Vass said he and his partners have, as part of their general research, identified some 30 compounds as significant in the human decomposition process. Seven of those were confirmed in Anthony's trunk, he said. Of those, Vass testified under cross-examination by Baez, only five were considered because the other two were at trace levels.
"The chloroform was shockingly high, unusually high," Vass said. The same testing done on a "control sample" of carpet from another Pontiac Sunfire, found in a junkyard, also showed chloroform, but the level was much lower -- "trace amounts," he testified.
Laser-based testing of the carpet, and testing of the other items also showed the presence of elements and substances associated with decomposition, he said. Found in the wheel well scrapings was acetic acid, a byproduct both of decomposition and of the manufacture of chloroform, according to Vass.
Vass said scientists used as a control sample a blanket that a 3-year-old's body had been wrapped in and put into a car trunk for three months. "The point of that was to confirm that compounds such as we saw in the Florida trunk, that were consistent with human decomposition, could be formed in that type of environment," Bass said.
In that test, four of the five compounds were present, he said. The only one not found was chloroform.
On cross-examination, Baez tried to suggest Vass had a financial interest in the case, which he denied, and also tried to cast doubt on the testing methods, protocols and quality control. He got Vass to admit he is not currently a member of any professional organizations.
Vass testified the odor in the air samples he received was "overwhelmingly strong. I was surprised that little can (containing the sample) had so much odor associated with it." He said he identified the odor as that of human decomposition.
On Saturday, FBI trace evidence examiner Karen Lowe testified that a single hair found in the trunk of Anthony's car was similar to that of Caylee and showed evidence of decomposition.
The scientific testimony, which began Friday, marked a departure from the dramatic testimony and evidence offered in the first nine days of the trial, in which friends and acquaintances contradicted Anthony's claims that she was frantically searching for her daughter during the month she was missing and before authorities were notified.
Instead, Anthony was staying with her boyfriend, spending time in Orlando with numerous friends, attending parties, going shopping and hitting nightclubs, including participating in a "hot body" contest, according to testimony in the case.
Her former boyfriend, friends and acquaintances have all testified that she did not mention her daughter being missing during that time and that they noticed nothing different about her demeanor.
According to testimony, Anthony asked her boyfriend to pick her up from the parking lot on June 27, saying the car had run out of gas. She also told a friend that she believed an animal carcass was lodged in her car's frame.
The car was towed to an impound lot on June 30, 2008, where a manager said he smelled the odor of decomposition.
Vass testified Monday that scientists "confirmed the carpet (in the trunk) was the point source of the odor."
Before prosecutors began presenting scientific evidence in the case on Friday, jurors watched recordings of jailhouse visits between Anthony and her parents.
In one conversation played Friday, Anthony scoffed at a media report her mother brought up speculating that Caylee had drowned in the family swimming pool.
"Surprise, surprise," Anthony said of the rumor, which is now the primary defense theory.
Anthony's defense team explains her behavior in the weeks following Caylee's death by saying she had been sexually abused by her father and had been taught to conceal her pain. George Anthony has denied abusing his daughter.
In Session's Michael Christian contributed to this report.
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