SANFORD, Florida (AP) - A video security expert has taken the witness stand in the George Zimmerman murder trial.
Greg McKinney is the first witness Friday as the trial enters a fifth day of testimony.
McKinney's company monitored the security cameras at the townhome complex where Zimmerman fatally shot 17-year-old Trayvon Martin last year.
After McKinney testified, two neighbors took the stand.
Jonathan Manlo, who went outside after hearing a gunshot, says Zimmerman asked him to call his wife and tell her that he shot someone. Manlo took cellphone photos of a bloodied Zimmerman and of Martin's body, and those photos were shown to jurors Friday.
He said Zimmerman didn't appear shocked, and that he acted calmly. It was after police arrived and handcuffed Zimmerman that Zimmerman asked him to call his wife.
Earlier, another neighbor, Jonathan Good, testified he heard a noise in back of his townhome, and he saw what looked like a tussle when he stepped out onto his patio to see what was happening.
He says he yelled, "What's going on? Stop it."
Zimmerman has claimed that he shot Martin in self-defense as the teen was banging Zimmerman's head on the ground. But Jonathan Good says he didn't see anyone being attacked that way.
Jurors already have been exposed to some of the state's biggest pieces of evidence, including the 911 call featuring cries for help prosecutors believe came from Martin.
On Thursday, a friend of Martin who had been on the phone with him when he was shot testified about what she heard during his confrontation with Zimmerman.