Tune in to HLN's "Nancy Grace" at 8 ET for live reports from Florida with all the details of the Casey Anthony trial. And follow the action on Nancy's special Casey Anthony trial page.
(CNN) -- Casey Anthony's defense attorneys are seeking to question a convicted felon who served prison time for kidnapping, claiming in court documents he is linked to Anthony's father through cell phone records.
Vasco Thompson, 52, is on an amended witness list filed Tuesday in Anthony's capital murder trial. Orange County Chief Judge Belvin Perry Jr. has not yet ruled on whether Thompson can be deposed or testify in the trial.
Casey Anthony's father, George Anthony, denied knowing Thompson or ever speaking to him in a statement released by his attorney.
Prosecutors allege that Casey Anthony, 25, killed her 2-year-old daughter Caylee in 2008 by using chloroform on her and putting duct tape over her nose and mouth. They allege she then put the little girl's body in black garbage bags and stored it in her trunk before dumping it in woods near her home.
Caylee's skeletal remains were found December 11, 2008. She was last seen June 16, 2008, but her disappearance was not reported until July 15, 2008, after Anthony's mother, Cindy Anthony, demanded answers from her daughter about Caylee's whereabouts.
Anthony faces seven counts in Caylee's death, including first-degree murder, aggravated child abuse and misleading investigators. If convicted, she could face the death penalty. She has pleaded not guilty.
"Mr. Thompson is a recently discovered witness through the ongoing efforts of defense investigators," according to the court documents filed Tuesday. "This witness was connected to George Anthony through his cell phone records."
A background check revealed that Thompson "has a violent criminal history and has served a 10-year prison sentence for kidnapping," according to the court documents.
"Because of the recently discovered and unexplained relationship between George Anthony and Vasco Thompson, their finite contact which, based on cell records, existed only during the relevant time period, and Mr. Thompson's violent criminal history, good cause is shown for the late disclosure of this witness," the defense says in the filing.
Those contacts, they allege, included four contacts on July 14, 2008 -- the day before Caylee was reported missing by Cindy Anthony.
The defense said it needs to question Thompson "to determine the existence of relevant admissible evidence in this trial."
Thompson refused to speak with defense investigators and called police when he was questioned, the documents said.
"Mr. Anthony does not know Vasco Dagama Thompson," the Anthonys' attorney, Mark Lippman, said in a statement. "Mr. Anthony does not recall ever speaking with Mr. Vasco Dagama Thompson at any time including July 14, 2008, by any form of communication."
Lippman pointed out the defense has failed to identify who initiated the calls or the length of time of each telephone call.
"This simply appears to be another attempt by the defense to attack my client," Lippman said. "Mr. Anthony has and will continue to maintain the position that he had nothing to do with the death of Caylee Marie Anthony or any of the events that occurred afterward regarding the actions of the defendant Casey Anthony established by the state of Florida in the presentation of their case."
According to records attached to the amended witness list, Thompson was sentenced in 1998 to 40 years in prison for kidnapping. He was required to serve eight years in prison and 30 years on probation. The Florida Department of Corrections website shows he was in and out of custody but was released in 2004.
It was unclear how Thompson might fit into the defense's strategy in the Anthony case.
Prosecutors rested their case earlier Wednesday, and Perry rejected a defense request for a judgment of acquittal, saying the jury must decide what to make of the evidence.
Casey Anthony's defense attorneys will begin presenting their case Thursday. The trial, held in Orlando, is in its fourth week.
The defense has said Caylee was not killed, but rather drowned in the family pool on June 16.
Defense attorney Jose Baez told jurors that Casey Anthony and George Anthony, panicked when they discovered the body and covered up her death. George Anthony rejected that scenario in his testimony the first week of the trial.
In arguing for acquittal, defense attorney J. Cheney Mason told Perry the state had failed to prove its case beyond a reasonable doubt and noted that evidence against Anthony is purely circumstantial.
In the past 3 1/2 weeks, jurors have heard testimony that was sometimes dramatic and other times complicated and scientific. They have seen grisly crime-scene photos of skeletal remains and received crash courses in computer forensics, forensic entomology and DNA testing.
Some of the most powerful testimony came from Anthony's former boyfriends, friends and acquaintances, all of whom saw her between June 16 and July 15, 2008.
During that time, according to testimony, Anthony was living at her boyfriend Tony Lazzaro's apartment, attending parties, hitting nightclubs, getting a tattoo that says "Bella Vita" -- Italian for "beautiful life" -- and shopping.
Numerous witnesses testified that they noticed nothing different in her demeanor, that she did not appear anxious or sad and that she did not mention Caylee except to provide different accounts of where she was -- most commonly, with her nanny, identified by Anthony as Zenaida Fernandez-Gonzalez.
Once an increasingly frantic Cindy Anthony tracked her daughter down and demanded answers as to Caylee's whereabouts, Casey Anthony told her family, as well as police, that Gonzalez had kidnapped Caylee and that she had spent the previous month frantically searching for her daughter.
The apartment Anthony led police to, claiming it was where Gonzalez lived, was vacant at the time. Police were never able to find the nanny. They did find a woman named Zenaida Gonzalez, who denied ever meeting Caylee or Casey Anthony and later sued for defamation.
"No one else benefited from the death of Caylee Marie Anthony," Burdick told jurors in her opening statements. "Caylee's death allowed Casey to live the good life, at least for those 31 days."
When Casey Anthony was asked by authorities, during the 911 call her mother made to report her granddaughter missing, why she waited 31 days to report the disappearance, Casey Anthony replied, "I have been looking for her and have gone through other resources to find her, which was stupid."
Gonzalez was one of a host of people Anthony apparently invented, complete with realistic-sounding details, according to testimony.
There was Jeffrey Hopkins, a wealthy suitor she told her mother she and Caylee were spending time with in Jacksonville, Florida, when in reality Caylee was missing and Casey Anthony had not left Orlando. One of Casey Anthony's acquaintances named Jeffrey Hopkins testified, saying he had never dated Anthony, that he was not wealthy and he had never lived in Jacksonville.
In addition, Anthony had claimed to be working at Universal Studios as an event planner through Caylee's disappearance. Testimony showed she had not worked there in years. A co-worker there, Juliette Lewis, whom Anthony said had a daughter Caylee's age, was also not found to exist.
Jurors heard from Anthony's former friend, Amy Huizenga, that her frustration level with her parents, particularly her mother, was rising around the time that Caylee disappeared. "I remember she told me her mom had told her she was an unfit mother," Huizenga said. "She was extremely upset about that."
She said Anthony also had to cancel plans "fairly frequently" when no one was available to watch her daughter.
However, the same friends, acquaintances and former boyfriend of Anthony's also said, when pressed by defense attorneys, that Anthony when seen with Caylee appeared to be a good and loving mother.
Anthony herself has appeared mostly stone-faced during testimony, but has broken down at times, wiping tears away or sobbing outright.
Jurors also heard evidence about Anthony's car, which she abandoned in late June, saying she had run out of gas. It eventually was towed from an Orlando business to a tow yard. Her parents picked it up July 15 after receiving a letter from the wrecker yard.
Numerous witnesses testified about a foul odor coming from the car -- a scent prosecutors allege stemmed from human decomposition. A dog trained to detect human remains alerted to the trunk, according to testimony, and compounds associated with human decomposition were found in the trunk.
One scientist, Arpad Vass of Tennessee's Oak Ridge National Laboratory, also testified that the level of chloroform found in testing of Anthony's trunk was "shockingly high."
Key forensic witnesses described in graphic detail the state of Caylee's remains when they were discovered in a wooded area less than a mile from the Anthony home, and jurors saw pictures of the child's skull; tiny, decaying shorts; and a "Winnie the Pooh" blanket found with the remains.
Animals had chewed on the little girl's bones by the time they were discovered, according to testimony. At times, Anthony ducked her head and tried to avoid looking at the graphic images.
Despite objections from defense attorneys, jurors saw a video in which images of Caylee's skull and the duct tape found across its mouth portion at the scene were superimposed over a photo of Caylee alive, smiling, with her mother.
Some of the most compelling testimony came from Dr. Jan Garavaglia, star of the Discovery Channel's "Dr. G. Medical Examiner" and chief medical examiner in the case. Garavaglia, who examined the child's remains, told jurors she could not say for sure how the child died, but homicide is "the only logical conclusion."
"The fact that it's tossed in a field to rot in bags is a clear indication that the body was trying to be hidden," Garavaglia said.
"It being put in a bag is a very big red flag for homicide, never seen in an accidental death for a child, and the fact that there's duct tape attached anywhere to that child's face is to me indication of a homicide."
An FBI latent print examiner testified that adhesive in the outline of a heart was found on the duct tape that covered the mouth portion of Caylee's remains. Sheets of heart-shaped stickers, with some stickers missing, were found at the Anthony home and introduced into evidence.
A sticker was also found at the site where Caylee's remains were discovered on a small piece of cardboard. An FBI analysis showed that sticker did not match those found at the Anthony home.
Jurors also heard about searches conducted on a computer at the Anthony home on March 17 and 21, 2008 -- several months before Caylee disappeared. They included "chloroform," "how to make chloroform," "household weapons" and "neck-breaking," according to testimony.
Other terms searched included "hand-to-hand combat" and "self-defense" and appeared uninvolved. "Chloroform" was searched for 84 times, according to the testimony of John Bradley, who developed a computer program used to locate the information.
Jurors heard from experts that a hair found in Anthony's trunk appeared similar to that of her daughter's, although the experts could not conclusively state that the hair was Caylee's. In addition, a forensic entomologist testified that tiny flies found in the trunk fit the theory that Caylee's body was stored there -- perhaps for three to five days.
Perry told jurors Monday that testimony in the case could conclude by the end of next week, although he cannot say for sure. Deliberations could begin by June 25, he said.
In Session's Mayra Cuevas, Cara Hutt and Michael Christian contributed to this report.
Watch Nancy Grace Monday through Sunday starting at 8 p.m. ET on HLN. For the latest from Nancy Grace click here.