(CNN) -- Jurors in the George Zimmerman trial got to hear his story again Tuesday, this time from Chris Serino, the lead Sanford police investigator in the case, and Zimmerman's best friend, Mark Osterman.

On the trial's seventh day in a Florida courtroom, both of them recounted the story Zimmerman told them about the confrontation with Trayvon Martin with minor variations.

Zimmerman, a former neighborhood watch captain, is charged with second-degree murder for killing 17-year-old Martin in Sanford, Florida, on February 26, 2012. Zimmerman told police he was pursuing the teenager throughout the neighborhood because there had been a series of break-ins in the area. The two fought, and Zimmerman said he was forced to draw his gun and kill Martin in self-defense.

Serino said he felt Zimmerman exaggerated the number of times he was hit that night but said he didn't feel any "active deception" on Zimmerman's part when he said he got out of his vehicle while pursuing Martin to see what street he was on.

Osterman, who wrote a book about the case, said that when he took Zimmerman home from the police station after the shooting, Zimmerman wasn't acting like himself. "He had a stunned look on his face. Wide-eyed, just kind of a little bit detached," Osterman said on the stand Tuesday.

Judge Debra Nelson started the day by asking jurors to dismiss Serino's earlier testimony in which he said he believed Zimmerman was being truthful about what happened the night he shot Martin.

The court reporter read the exchange between defense attorney Mark O'Mara and Serino, a detective with the Sanford Police Department.

"So if we were to take pathological liar off the table as a possibility, you think (Zimmerman) was telling the truth?" asked O'Mara.

"Yes," said Serino.

The judge told jurors to dismiss the question and the answer, telling them it was an improper statement made by the witness about Zimmerman's credibility.

On his second day on the stand, Serino was asked by prosecutor Bernie de la Rionda if he thought Zimmerman was profiling Martin.

"If I were to believe that somebody was committing a crime, could that not be profiling that person?" asked de la Rionda.

"It could be construed as such, yes," said Serino.

"Was there any evidence that Trayvon Martin was committing a crime that evening, sir?" asked de la Rionda.

"No, sir," said Serino.

"Was there any evidence that that young man was armed?" asked de la Rionda.

"No, sir," said Serino.

The prosecutor also wanted to know Serino's thoughts on the language Zimmerman used in his non-emergency call to police when he said, "these (expletive) punks always get away."

"Is that something you would use in reference to somebody that you're going to invite over to dinner?" asked de la Rionda.

"No, sir, I would not," said Serino.

"Does that seem like a friendly comment about somebody else?" asked de la Rionda.

"No, sir, it does not," said Serino.

Serino also agreed that calling someone "(expletive) punks" is ill will and spite. To prove second-degree murder, prosecutors have to show Zimmerman acted with a "depraved mind" without regard for human life.

The prosecutor then started to dig into some of the details of Zimmerman's statement on the shooting to police, asking Serino about inconsistencies.

Serino said there was evidence to suggest that Zimmerman was still following Martin after the non-emergency operator told him not to. And Serino said red flags were raised for him when Zimmerman didn't know the names of the streets in his neighborhood, because there are only three.

However, Serino also said that he didn't feel there was "active deception" on Zimmerman's part when he said he didn't know where he was and had to get out of his vehicle to look at a street sign.

About the fight that allegedly ensued between Zimmerman and Martin, Serino also said Zimmerman's nose may have been bleeding back into his mouth, which could explain why Martin didn't have blood on his hands. And he agreed with O'Mara that the purported smothering of Zimmerman by Martin could have happened only momentarily, perhaps not long enough to be heard on the 911 call made by a neighbor.

When questioned again by the prosecution, Serino admitted that he was speculating on the details of how the fight played out.

The last witness to take the stand before court recessed for lunch was Mark Osterman, who called Zimmerman "the best friend I've ever had."

Osterman has worked in law enforcement for more than 20 years and said he's the one who helped Zimmerman purchase his gun. "He asked whether he should or shouldn't -- to start with -- and I recommended that he should. Anybody who's a non-convicted felon should carry a firearm. The police aren't always there," said Osterman.

Osterman also recounted the story of the shooting that Zimmerman told him. He said that as the two scuffled, Zimmerman's jacket came up, potentially exposing his gun to Martin. Osterman said Zimmerman was mostly focused on Martin's hands, which he said were keeping him from breathing.

"It was critical. He was losing oxygen. He felt he was not able to breathe. That's why he was desperate to clear an airway," said Osterman.

Osterman said Zimmerman felt Martin grab either his gun or the holster.

"That's when he had to -- he freed one of his hands and got the gun. He either broke contact or knocked Trayvon's hand away, and then he drew it," said Osterman.

Osterman said Zimmerman shot Martin, crawled out from under him, holstered his weapon, got on Martin's back and held his arms out, pinning them down.

But a photograph snapped by a neighbor shows Martin's hands under his body. Osterman said he wasn't aware of this fact.

Martin died of a single gunshot wound to the chest.