The family of Trayvon Martin is asking the FBI to get involved in the investigation of the killing of the unarmed 17-year-old Florida high school student, who was shot last month by a self-appointed neighborhood watchman outside his stepmother's home.
Martin, a black high-school junior, was making his way home with a bag of Skittles and a can of iced tea on Feb. 26 when George Zimmerman spotted him, called a non-emergency dispatch number to report Martin looked intoxicated, followed him, and then minutes later after an altercation, shot him.
Zimmerman, 28, who is white, claimed self defense. He was never arrested and has been charged with no crime, sparking national outrage.
ABC News has learned police seemed to accept Zimmerman's account at face value that night and that he was not tested for drugs or alcohol on the night of the shooting, even though it is standard procedure in most homicide investigations.
Now Martin family attorney Ben Crump has written a letter to Attorney General Eric Holder, and it's being circulated by several members of congress who are putting pressure on him to get the FBI involved.
An FBI spokesman told ABC News: "We are aware of the incident, we have been in contact with local authorities and are monitoring the matter."
The night of Feb. 26, Zimmerman made a non-emergency call to police before fatally shooting Martin, in which he told a dispatcher, "This guy looks like he's up to no good, on drugs or something."
But law enforcement expert Rod Wheeler who listened to the tapes tells ABC News that Zimmerman, not Martin, sounded intoxicated in the police recordings of the 911 calls.
"When I listened to the 911 tape the first thing that came to my mind is this guy sounds intoxicated. Notice how he's slurring his words. We as trained law enforcement officers, we know how to listen for that right away and I think that's going to be an important element of this entire investigation," Wheeler said.
But Zimmerman was not tested.
Martin's family is now calling on the FBI to take over what they say is a botched investigation.
"We've got a fair investigation, it was the best we can do, it's in states attorney hands now," Sanford Police Department spokesman Dave Morgenstern said.
Series of Calls to Police Record Events Leading Up to Shooting
The series of calls to police, which depict the apparent progression of events that led to Zimmerman allegedly shooting Martin, sent the boy's mother screaming from the room and prompted his father to declare, "He killed my son," according to a family representative.
The contents of the calls and the family's reaction to them were recounted to ABC News by a representative of the boy's family, Ryan Julison, and ABC News affiliate WFTV published excerpts from the 911 calls.
On one call to a non-emergency dispatch number, according to Julison, Zimmerman says, "He's checking me out," and then, "This guy looks like he's on drugs, he's definitely messed up."
"These a**holes always get away," he adds.
The dispatcher is heard trying to discourage Zimmerman, asking, "Are you following him?.. Okay, we don't need you to do that."
Within minutes, however, 911 calls are being made to police reporting the two are fighting.
"They're wrestling right in the back of my porch," one frantic caller says. "The guy's yelling help and I'm not going out."
On a second call someone's screams for help can be heard and what sounds like two gunshots.
The caller's boyfriend shouts, "Get down," and after the second apparent gunshot, the shouts for help cease, Julison told ABC News.
"There's gun shots. Uh, I'm pretty sure the guy is dead out here, holy sh**," a caller says into the phone.
One witness describes Zimmerman after the shooting.
"He's out there with a flashlight. The guy is raising his hands up saying he shot the person," the caller said.
Martin's family listened to eight tapes, Julison said. At one point, Sybrina Fulton, Trayvon's mother, ran out of the room screaming and crying, barely lasting through half the tapes.
The boy's father, Tracey Martin, stoic and measured until then, erupted, Julison said.
"He killed my son," Martin said, according to Julison. "He killed my son. He couldn't control himself."
The Sanford, Fla., Police Department, relenting to massive public pressure, plans to release parts of the 911 tapes pertaining to the shooting, multiple sources told ABC News, but wanted the boy's family to hear the tapes before they were released to the public, according to a family source.
A week after ABC News uncovered questionable police conduct in the investigation of the fatal shooting, including the alleged "correction" of at least one eyewitness' account, outrage that the shooter remains free is intensifying.
"It's surprising. It's shocking," said Tracy Martin, Trayvon's father. "It lets me know that justice is just not being served here. All we want is justice for our son. We're not asking for anything out of the ordinary."
In an interview with ABC News, Martin's mother, Fulton, tearfully said she only seeks an arrest.
"Let a judge and jury decide the rest," she added.
In the meantime, outrage is spreading across the Internet.
The Seminole County State Attorney's Office was so bombarded by emails demanding that it prosecute Zimmerman that its website had to be taken down for 45 minutes, according to a spokeswoman for the office.
One of several petitions for Zimmerman's arrest has garnered more than 250,000 signatures on a change.org site, and at one point signatures were pouring in at the rate of 10,000 an hour, according to the website.
The outrage has been partly buoyed by calls for non-violent action by hip-hop luminaries, including Russell Simmons, who has been tweeting about the tragedy and warning against its possible vigilante violence.
"Trayvon Martin didn't die so we can create a race war he died so we can promote better understanding. We must start honest dialogue," Simmons wrote.