George Zimmerman's DNA was not found under Trayvon Martin's fingernails and there was no trace of the teen's on the gun



Pranksters who saw Skype handle of witness on TV interrupted testimony with pings and call boxes

Former professor reveals Zimmerman said he wanted to become an attorney and then prosecutor

Judge Nelson stopped proceedings and testimony continued by phone

School records were ruled admissible in court as prosecutors tried to prove Zimmerman knew about Stand Your Ground law

Got an A in the class that taught it



He previously applied for a job with the police but was turned down because of bad credit



A crime lab analyst testified today that none of George Zimmerman's DNA was found under Trayvon Martin's fingernails, nor was the teen's found on the gun that killed him.

Florida Department of Law Enforcement DNA expert Anthony Gorgone told the court that tests of Zimmerman's gun revealed the neighborhood watch volunteer's DNA on the firearm's grip - but not Trayvon Martin's.



Zimmerman claims the teen was reaching for his firearm during the fight when he fired the gun into Martin's chest in self defense.

The prosecution spent this afternoon refuting this claim with forensic evidence.

Scroll down for videos

Argue: Prosecutors said Zimmerman's ability to understand criminal investigations and desire to be a police officer doesn't show wrongdoing, but is relevant to Zimmerman's state of mind on the night Martin was killed

DNA: Florida Department of Law Enforcement Crime Lab Analyst Anthony Gorgone points to a shirt worn by George Zimmerman on the night he shot Trayvon Martin

Evidence: Gorgone said Zimmerman's DNA was found on Trayvon's hoodie and in the sweatshirt he wore underneath. He did not, however, find any on the cuffs of the teen's hoodie

Crucial evidence: Assistant state attorney Bernie de la Rionda shows DNA samples to the jury

Analyst: Gorgone told the court that tests of Zimmerman's gun revealed the neighborhood watch volunteer's DNA on the firearm's grip - but not Trayvon Martin's

Gorgone also revealed that Zimmerman's DNA was found on Trayvon's hoodie and in the sweatshirt he wore underneath.



He said there was not, however, any on the cuffs of the teen's hoodie. Bernie de la Rionda tried to hammer home that if Trayvon was beating Zimmerman with his hands, there would have been DNA on the cuffs of his clothes.

On cross examination, Gorgone acknowledged that Trayvon's clothes were improperly stored as they were put in a plastic bag while wet.

He explained it would have been better to let them dry out first or use paper bags.



Earlier today the trial was thrown into disarray when a witnesses Skype testimony was interrupted by a steady stream of calls from different users, who likely knew their name would appear on TV.

Gordon Scott Pleasants, a professor from Seminole State College of Florida, taught the accused murderer an online criminal investigations class, in which Zimmerman revealed he wanted to become an attorney and eventually a prosecutor.



As he was being cross examined by the defense, a number of incoming call boxes began popping up on screen, accompanied by a loud ping.

At one point Pleasants' face could not be seen as the barrage of calls appeared on the screen, which was being projected to the court - and on live TV.



Witness: Gordon Pleasants - who taught George Zimmerman a criminal investigations class - had to give his testimony via Skype because he is in the Colorado desert

Interruption: Names started to pop up on the screen - that was being projected to the court - and even when Pleasants hung up, the same people continued to call, with more and more joining in

All smiles: George Zimmerman and defense attorney Mark O'Mara talk during an early morning recess in Zimmerman's trial in Seminole Circuit Court, in Sanford on Wednesday

Even when Pleasants hung up or 'declined', they kept calling back, with more and more joining in as he attempted to testify.



Calls from 'Salman Talpur', 'Tay', 'Marcus' and other pranksters flooded in. It is unclear if they are friends of Pleasants or people who saw his Skype handle on TV.



Mark O' Mara commented: 'There's now a really good chance we are being toyed with.'

The incident incited laughter from the court and Judge Debra Nelson grew noticeably agitated as she told the witness to hang up. They then continued the testimony by regular phone call.

When Pleasants apologized for the interruption, defense attorney Mark O'Mara said: 'It looks like a dozen people were trying to call you once they realized their name would be on TV.'

Earlier, Zimmerman's school records and his interest in law enforcement - as well as his unsuccessful police job application - was deemed admissible as evidence by the judge.

Prosecutors called a military prosecutor who taught a criminal procedure class at Seminole State College in which Zimmerman earned an A.

Alexis Francisco Carter, an officer in the U.S. military JAG corps, told the court Zimmerman was 'probably one of the better students in the class'.

When defense attorney Don West cross-examined Carter, and pointed out Zimmerman at the defense table, the military lawyer smiled at the defendant and said: 'How you doing, George?'



Former teacher: Capt Alexis Francisco Carter, an officer in the U.S. military JAG corps, told the court Zimmerman was 'probably one of the better students in the class'

Solemn: Trayvon Martin's parents Tracy Martin, left, and Sybrina Fulton, enter the courtroom after a recess on Wednesday, July 3, 2013

Greeting: Zimmerman shakes the hand of one of his legal team, defense attorney Mark O'Mara, before his trial started on Wednesday

Both Carter and Pleasant's testimony was intended to highlight to the court that Zimmerman knew Florida's Stand Your Ground Law - which says there is no duty to retreat if one is confronted with potentially lethal force.

Zimmerman had maintained in an interview with Fox News last year that he did not know about the law.



A job application Zimmerman made to the Prince William County police department in Virginia in 2009 was also presented to the court, as was an application to ride around with Sanford police officers in 2010.

The court heard the 29-year-old's job application was rejected because he had a bad credit score.

Prosecutors also began a detailed questioning on the forensics analysis performed on Zimmerman's gun after calling Florida Department of Law Enforcement analyst Amy Siewert to the witness stand.



She testified that residue and tearing on Martin's sweatshirt showed Zimmerman's gun was touching Martin's chest when it fired.



Demo: Amy Siewert, a firearms expert with the Florida Department of Law Enforcement, demonstrates George Zimmerman's gun during the trial

From Arizona: Gordon Scott Pleasants gives his testimony via Skype during the George Zimmerman trial in Seminole Circuit Court before hanging up due to internet trolls

Evidence: Trayvon Martin's sweatshirt is shown on the screen as a firearms expert talks about the gunpowder placement and that the gun would have been pressed into the teen's chest

She also demonstrated for jurors how the gun is fired by holding the 9 mm semi-automatic handgun, and under cross-examination, said the gun was safe to carry around loaded because it won't fire unless the trigger is pulled.

Prosecutors said Zimmerman's ability to understand criminal investigations and desire to be a police officer doesn't show wrongdoing, but is relevant to Zimmerman's state of mind on the night Martin was killed.



'He has applied to be a police officer before, he still wants to be one, according to some of his homework assignments...this wasn't some sort of passive thing,' said prosecutor Richard Mantei, who noted Zimmerman took a course on how to be a good witness and expressed a desire to go on police ride-alongs. 'This is simply a fact the jury ought to know.'



When he was interviewed by detectives, Zimmerman spoke 'in written police jargon' and talks about 'justifiable use of force' and says he 'unholstered my firearm, not I pulled my gun', Mantei said.

The trial continues on Friday when the prosecution are expected to rest.



Yesterday, a medical examiner told the court the injuries sustained by George Zimmerman on the night Trayvon Martin was killed were 'very insignificant' and 'not life threatening'.



Dr Valerie Rao, a Jacksonville-based medical examiner who did not directly examine Zimmerman but reviewed evidence in the case, was cross examined about the extent of his wounds and what kind of force would have caused it.

Explaining the cuts on his head, she said though they were consistent with being hit against concrete, they were not consistent with being repeatedly slammed against the ground.

'The injuries are not from great force,' she said.

Dr Valerie Rao, a Jacksonville-based medical examiner who did not directly examine Zimmerman but reviewed evidence in the case, was cross examined about the extent of his wounds and what kind of force would have caused it

Expert: Dr Rao explains Zimmerman's injuries to the court, which she said are not consistent with being slammed against the concrete

Defendant: George Zimmerman arrives for the 17th day of his trial in Seminole circuit court, in Sanford, Florida. He is charged with second-degree murder in the fatal shooting of Trayvon Martin

Prior to this, jurors were shown the television interview Zimmerman gave to Fox news anchor Sean Hannity last year, as the prosecution sought to once again highlight inconsistencies in his version of events.

In the interview, Zimmerman said he did not pursue Trayvon but just meant that he was going in the 'same direction as him' when he told the 911 dispatcher that he was actually following him when asked.

He also said in the interview that he believed what happened was 'all God's plan', a comment that sparked widespread controversy after the interview was aired.



The lead detective in the shooting returned to the stand yesterday where he was questioned about inconsistencies in George Zimmerman's account, and said there were just a few minor details.



He is considered a key witness in the neighborhood watch volunteer's murder trial as he was the person who initially said Trayvon's death was 'avoidable' and suggested manslaughter charges for Zimmerman.

He later claimed he was pressured by other officers to say this.

Prosecutor Bernie De la Rionda questioned the detective about the opinion he gave on Monday that he didn't believe Zimmerman displayed any ill will or spite to Martin.

Detective: Sanford police officer Chris Serino was the lead detective in the case and testified for the second time today in Zimmerman's trial

Prosecutor: Bernie de la Rionda questions Sanford police officer Chris Serino about inconsistencies in Zimmerman's statements

Mock punching: Prosecutor Bernie de la Rionda demonstrates a possible scenario while questioning state witness Chris Serino

Prosecutors must prove there was ill will, spite or a depraved mind by the defendant to get a second-degree murder conviction.

De la Rionda played back a police call Zimmerman had made to report Martin in the neighborhood. Zimmerman uses an expletive and 'punks' and then says, 'These a**holes. They always get away.'



The prosecutor asked the investigator if those words showed some spite, and Serino said 'a little'.

Next, de la Rionda challenged Serino's contention that he found Zimmerman's story without major inconsistencies.



Zimmerman's police interview in which investigators question him about small differences in the neighborhood volunteer's story was played back.



The prosecutor also pointed out Zimmerman claimed that after he shot Martin, he spread out the teen's arms. But a photo taken immediately after the shooting shows Martin's arms under his body.



'Is that inconsistent with the defendant's statement he spread the arms out?' de la Rionda asked.



'That position, yes it is,' Serino said.



Instructions: Judge Debra Nelson instructs the jury to disregard a portion of testimony from state's witness and Sanford police officer Chris Serino from the previous day

Defense attorney: Mark O'Mara, right, questions Sanford police officer Chris Serino, left, during the George Zimmerman trial today as he shows him a map of the gated community

Family: The parents of Trayvon Martin, Sybrina Fulton, center, and Tracy Martin, right, with Trayvon Martin's Aunt, Stephanie Fulton Sands, left, stand for the jury's arrival

It was Serino's second day on the witness stand. He and another investigator, Doris Singleton, testified on Monday about their investigation as jurors heard a series of police interviews in which the detectives grew more pointed in their questioning.



In an early interview, just hours after the February 26, 2012, shooting, Singleton recounted that Zimmerman noticed a cross she was wearing and said: 'In Catholic religion, it's always wrong to kill someone.'



Singleton said she responded, 'If what you're telling me is true, I don't think that what God meant was that you couldn't save your own life.'



But in an interview days later, Singleton and Serino suggest that Zimmerman was running after Martin before the confrontation.



They also ask Zimmerman why he didn't explain to Trayvon why he was following him. The officers insinuate that Martin may have been 'creeped out' by being followed.



'Do you think he was scared?' Singleton asked Zimmerman in one video interview.



Under cross-examination, though, Serino said Zimmerman seemed straightforward in his answers and didn't show any anger when talking about Trayvon.



Evidence: A reenactment video showing George Zimmerman with Sanford police investigators taken the day after the Trayvon Martin shooting, is projected for the jury yesterday

Interrogation: A video of George Zimmerman being interviewed at the Sanford police station by Officer Singleton is projected on a video monitor for the jury yesterday

Evidence: A video of George Zimmerman giving a DNA sample at the Sanford police station with bandages visible on the back of his head is shown to the jury

Sanford police officer: Doris Singleton holds up a copy of a photo of the complex where the Trayvon Martin shooting took place as she testified yesterday

Claims: Zimmerman told the police officer that he lost track of Trayvon and got out of his truck to look for a street name he could relay to a police dispatcher

Serino said the increasingly pointed questioning is a tactic known as a 'challenge interview', where detectives try to break someone's story to make sure they're telling the truth.

In his first interview at the police station, Zimmerman said he saw Martin walking through his neighborhood on a dark, rainy night while he was driving to the grocery store.



He told Singleton that he didn't recognize Trayvon and that there had been recent break-ins at his townhome complex.



Zimmerman told the police officer that he lost track of Trayvon and got out of his truck to look for a street name he could relay to a police dispatcher.



When the dispatcher suggested he didn't need to follow Trayvon, he started to head back to his vehicle.



At that point, Zimmerman alleged, the teen jumped out of some bushes, punched him and he fell to the ground.



Zimmerman said Trayvon then began hitting his head against the sidewalk as Zimmerman yelled for help before he was told: 'You're going to die tonight mother f***er.'



With Zimmerman's shirt and jacket pushed up during the struggle and his holstered gun now visible, he thought Trayvon was reaching for his firearm around his waist.



Zimmerman told the officer that he shot the teen who then said: 'You got me.'

Zimmerman has said he fatally shot the unarmed black teen in self-defense in February, 2012, because he says Martin was banging his head into a concrete sidewalk behind townhomes in a gated community.



He faces life in prison if convicted of second-degree murder.



The state argued during its opening statement that Zimmerman profiled and followed Martin in his truck and called a police dispatch number before he and the teenager got into a fight.



Zimmerman has denied the confrontation had anything to do with race, as Martin's family and their supporters have claimed.

