Trayvon Martin's Last Phone Call Triggers Demand for Arrest 'Right Now' Martin family lawyer Benjamin Crump says arrest George Zimmerman "right now."

SANFORD, Fla., March 20, 2012 -- A phone call from slain black teenager Trayvon Martin to his girlfriend seconds before he was shot dead by a self-appointed neighborhood watch captain "blows ... out of the water" the shooter's self-defense claim and he should be arrested "right now," a lawyer for Martin's family said today.

Attorney Benjamin Crump spoke after ABC News reported exclusively the existence of a phone call between Martin and his girlfriend, which detailed the last terrifying moments of Martin's life as he was pursued, accosted and shot dead by George Zimmerman.

Police accepted Zimmerman's claim of self-defense and have charged him with no crime.

"This young lady connects the dots," said Crump. "Arrest George Zimmerman for the killing of Trayvon Martin in cold blood, today.

"We don't understand how he's not arrested. The family worries that the more time passes it will be swept under the rug," the lawyer said.

Martin's death Feb. 26 has stirred national outrage and protests, partly prompting the U.S. Justice Department's Civil Rights Division and the FBI to open an investigation into the case.

Florida State Attorney Norm Wolfinger announced today that he had ordered an "expeditious review" of the investigation conducted by the Sanford Police Department, and that he would be "utilizing the investigative resources of the Seminole County Grand Jury, which will be called to session" next month.

ABC News was there exclusively as the 16-year-old girl told Crump about the last moments of the teenager's life. Martin had been talking to his girlfriend all the way to the store where he bought Skittles and a tea. The phone was in his pocket and the earphone in his ear, Crump said.

"He said this man was watching him, so he put his hoodie on. He said he lost the man," Martin's friend said. "I asked Trayvon to run, and he said he was going to walk fast. I told him to run, but he said he was not going to run."

Eventually, he would run, said the girl, thinking that he'd managed to escape. But suddenly the strange man was back, cornering Martin.

"Trayvon said, 'What are you following me for,' and the man said, 'What are you doing here.' Next thing I hear is somebody pushing, and somebody pushed Trayvon because the head set just fell. I called him again, and he didn't answer the phone."

The line went dead. Besides screams heard on 911 calls that night as Martin and Zimmerman scuffled, those were the last words he said.

Trayvon's phone logs, also obtained exclusively by ABC News, show the conversation occurred five minutes before police first arrived on the scene. Crump said the girl's identity was being withheld because "her parents are gravely concerned about her health and her safety." Her parents asked that only an attorney be allowed to ask her questions.

Martin's father, Tracey Martin, and mother, Sybrina Fulton, listened to the call, along with ABC News, ashen-faced.

"He knew he was being followed and tried to get away from the guy, and the guy still caught up with him," Tracey Martin said. "And that's the most disturbing part. He thought he had got away from the guy, and the guy backtracked for him."

The girl was so distraught after the killing that she spent a night in the hospital, the lawyer said.

"She was really traumatized over this. They were dating. ... It's a situation where to know you were the last person to talk to the young man who was one of the most special persons in the world to you," Crump said.

The lawyer said he would give the details of the phone call to the federal investigation.

"We're going to turn this over to the Justice Department because the family does not trust the Sanford Police Department to have anything to do with the investigation," said Crump.

Zimmerman killed Martin as Martin walked back to his father's fiance's home after stepping out to buy snacks during the NBA All-Star Game. After weeks of relentless pressure, the Sanford Police Department at last released emergency and nonemergency calls placed during the attack.

"These a**holes always get away," Zimmerman said in a call to a nonemergency number.

Dispatcher: "Are you following him?"

Zimmerman: "Yeah."

Dispatcher: "We don't need you to do that."

An altercation soon ensued. A few moments later a torrent of 911 calls flooded in and Martin was killed by a single bullet. Zimmerman claimed self-defense and has yet to be arrested, stoking outrage and claims of prejudice against the police department.

"When George Zimmerman is arrested, tried and convicted I will get a little rest," Tracey Martin said.

Phone records that indicate the time of the girl's call with Trayvon Martin before his death.

Nearly half a million people have signed an online petition on change.org urging law enforcement officials to step in and arrest Zimmerman, who violated major parts of the Neighborhood Watch Manual, which states "It should be emphasized to members that they do not possess police powers. And they shall not carry weapons or pursue vehicles."

There are about 22,000 registered watch groups nationwide, and Zimmerman was not part of a registered group, which police were not aware of at the time of Martin's killing, said Chris Tutko, the director of the National Neighborhood Watch program.

Protests have played out in the Florida town all week with a large gathering expected Thursday.

Hear More of the Phone Call With Trayvon Martin's Girlfriend and Martin Family Attorney Benjamin Crump