George Zimmerman suffered a fractured nose, two black eyes, cuts to the back of his head and a back injury on the night he shot and killed Trayvon Martin, according to a doctor who examined him the day after the fatal confrontation.

A medical report newly released by prosecutors in Florida gives the clearest picture yet of the injuries the neighbourhood watch leader claims he sustained during the altercation with the unarmed teenager on 26 February.

Zimmerman, 28, was not arrested at the time but was later charged with second-degree murder. His lawyers insist he acted in self-defence and that the killing was justified under Florida's controversial stand-your-ground law, which allows for lethal force in life-threatening situations.

The doctor's three pages of notes reveal that Zimmerman came to his surgery in Sanford the morning after the shooting, seeking treatment for two cuts to the back of his head, one about an inch long and the other a quarter-inch.

He also reported bruising to his upper lip and cheek and pain in his lower back and complained of stress and "occasional nausea when thinking about the violence".

Zimmerman's lawyer, Mark O'Mara, is expected to try to use the report to back up his claims that it was Martin, a 17-year-old high school student, who provoked the confrontation and punched his client in the face before repeatedly slamming his head into the pavement.

Until now, grainy and inconclusive video footage of Zimmerman at the Sanford police station soon after the shooting, and neighbours' accounts of seeing him with a bandaged head and nose, have provided the only public clues to the extent of his injuries.

The doctor wrote that it was "imperative" that Zimmerman saw a psychologist for evaluation, and also recommended that he follow up with an ear, nose and throat specialist, advice that was declined.

Zimmerman has been in hiding since he was freed on $150,000 bail at a hearing on 20 April, nine days after his arrest.

State attorney Angela Corey, who charged him with murder after weeks of angry public protests in Florida and elsewhere, said Zimmerman initiated the confrontation with the boy.

Martin, who lived in Miami but who was staying at the house of his father's friend in the Retreat at Twin Lakes gated community in Sanford, was walking home with sweets and an iced tea he bought at a local shop. Zimmerman called police to report a suspicious male, and screaming and a single gunshot were recorded on subsequent 911 calls from neighbours.

O'Mara is poring over hundreds of police and witness statements and other documents, videos and photographs released to him on Monday, but said he would not discuss the contents publicly.

"It is inappropriate for us to comment on particular pieces of evidence," he said in a statement on his website.

Prosecutors have also yet to release details, but an eight-page summary of evidence made available by Corey's office on Tuesday lists 67 CDs worth of digitised documents, including Martin's post-mortem report, said to reveal broken skin on his knuckles, and video recordings of Zimmerman's questioning by police.

It also includes details of evidence taken from Zimmerman after the incident, including his gun and bullets, a DNA sample, and mobile phone records.No date has been set for a trial; if convicted, Zimmerman could be jailed for at least 25 years.

Zimmerman's father, meanwhile, has spoken of how the family's life "will never be the same" regardless of the outcome of the case.

Retired magistrate Robert Zimmerman said he was on the run with his wife and mother-in-law, checking into hotels under assumed names to escape death threats sent to their home.

"All of a sudden, it's pack up what you can and leave," he said in an interview with the Miami Herald. "Staying in this hotel room or that hotel room. It's been unimaginable. Our lives will never be the same."

© Guardian News and Media 2012

[Booking photo of George Zimmerman via AFP]