What happened the night of Trayvon Martin's death?

Attorney Ben Crump releases audio testimony from Martin's girlfriend

February 26: Trayvon Martin killed. George Zimmerman questioned by Sanford Police and released.

SANFORD, Fla. – A news conference on Tuesday by the lawyer for the family of the teen who was shot and killed by a neighborhood watchman shed light into what happened and what police may have been lacking to make an arrest.

Attorney Ben Crump provided audio testimony from a witness who was on the phone with 17-year-old Trayvon Martin when he encountered 28-year-old George Zimmerman.

Martin was shot and killed last month in a confrontation with neighborhood watch leader George Zimmerman while walking from a store in Sanford after purchasing a bag of Skittles and an iced tea.

It appears from 911 calls that Martin died from a shot fired at almost exactly 7:17:11 p.m., seven and a half minutes after Zimmerman called the sheriff's office.

Records show Zimmerman's first call to authorities was at 7:09:34 p.m., followed by seven witness calls at 7:16:11, 7:16:41, 7:17:06, 7:17:15, 7:17:54, 7:18:00 and 7:19:04.

According to the calls released last week, dispatchers told Zimmerman not to follow Martin. But Zimmerman did follow him for about 100 seconds down the street until the audio is cut when Zimmerman and the sheriff's office end their call at 7:14 p.m. That leaves a 3-minute gap between the call and the shooting.

By the time the first 911 call comes in at 7:16:11 p.m. in the background of the audio you can hear a struggle.

At 7:17 p.m. the calls about residents hearing gunshots start coming in, less than a minute before the first Sanford police units arrive.

Zimmerman told authorities he was blindsided from his left and attacked after he lost sight of Martin and began walking back to his SUV.

Police said they couldn't arrest Zimmerman because they had no one refuting that claim until Tuesday, when Crump released the interview he had gotten with the girlfriend of Martin he says Martin was talking to at the time Zimmerman approached him.

Crump played the audio files of the girlfriend, whose identity won't be released because of her age, in which she said Martin told her "I think this dude is following me," and slowed down to see who it was. She says she then told him to "be careful and just run home."

She said Martin tried to lose Zimmerman and thought he did. He then said "Oh he's right behind me again," according to her testimony, before asking Zimmerman "Why are you following me?"

She said she heard another voice say " What are you doing around here?" According to her audio testimony, the girl then said someone pushed Martin down because the headset for his phone fell off.

The girl's testimony directly contradicts what Zimmerman told police happened and leaves many, including the supporters of justice for Trayvon, wondering why Sanford police didn't talk to the girl before the Martin family attorney did.