Trayvon Martin walked into a 7-Eleven in Sanford, Florida, grabbing a bag of Skittles and a can of Arizona iced tea. The hood from his dark gray sweatshirt over his head, he walked up to the counter, reached deep into his pants' pockets, paid the clerk, then walked out.

This seemingly mundane act, captured on a surveillance video, would be the last image the 17-year-old's loved ones would have of him alive.

While questions still remain, what happened next to Martin on the night of Feb. 26 became clearer on Thursday with the release of scores of pages of investigative and medical examiner's reports, in addition to new images of Martin's shooter and the 7-Eleven video.

Martin didn't live in Sanford, a central Florida city of about 53,000 people. Yet by that winter night, he'd been there for seven days, after being suspended for the third time from Dr. Michael M. Krop High School in Miami, in this instance, for 10 days after drug residue was found in his backpack, according to records obtained by the Miami Herald.

His father Tracy had taken his son four hours away from home because neither he or Trayvon Martin's mother wanted the teen to stay in his hometown where he could enjoy time with his friends, family friend and former football coach Jerome Horton recalled later.

That Sunday night, Martin was supposed to be getting a snack and heading back to the Sanford home of his father's fiance.

It was on that walk back that he encountered George Zimmerman, a 28-year-old neighborhood watch volunteer.

Some details as to Martin's thought process around that time may someday be gleaned from what he told his girlfriend back in Miami in a cell phone conversation, his family's lawyers said.

The boyfriend and girlfriend spoke at 7:12 p.m.

Zimmerman's voice, meanwhile, comes through on a 911 call he made around that time, telling a dispatcher about "a real suspicious guy."

"This guy looks like he's up to no good, or he's on drugs or something. It's raining, and he's just walking around."

The dispatcher asked Zimmerman, who'd called 911 at least four times previously for other incidents, if he was following the person. He replies, "Yes."

"OK. We don't need you to do that," the dispatcher responded.

But Zimmerman followed him anyway.

What happened next is a matter of dispute. Martin and Zimmerman were obviously in the middle of it, but no one else saw all that happened. One witness later told police that "she heard a commotion, which sounded like arguing," while another mentioned "loud talking."

And on one 911 call, placed by a neighbor, a police sergeant counted one man yelling "help!" or "help me!" 14 times in a span of 38 seconds.

Who was yelling? When the 911 calls were later played back for him and he was asked if they were from his son, an emotional Tracy Martin "quietly responded 'no'." But an FBI analysis, also detailed on Thursday, said it couldn't be determined whose voice it was due to the "extreme emotional state" of whomever was yelling, a lack of words from which to compare, overlapping voices and "insufficient voice quality" on the recording.

The same analysis also didn't reach conclusions as to whether Zimmerman used a racial epithet to describe Martin on his own 911 call, as some have alleged. Martin's family have said they believe Zimmerman, a white Hispanic, profiled the African-American teen.

Numerous witness, however, did clearly hear a gunshot.

It came from Zimmerman's black, 9mm semiautomatic hand gun. The bullet went into Martin's left chest and lodged there.