24/03/2012 11:13 GMT | Updated 24/05/2012 06:12 BST

Florida Shooting Trial: British Murders Suspect Shawn Tyson's Sister Samantha Huffman Charged Over Facebook Post

The sister of a teenager on trial accused of murdering two British tourists in Florida has been charged with retaliating against a witness, reportedly in connection with comments she made on Facebook.

Samantha Huffman is believed to have been arrested over a comment on the social networking website, directed at Nakeira Keno, 21, who gave evidence in the trial of Shawn Tyson earlier this week.

Tyson, 17, is accused of shooting James Kouzaris and James Cooper as they walked through the Newtown area of Sarasota in April last year.

Ms Keno told the court on Thursday that she saw the men walking through the public housing complex known as The Courts just before the shootings in the early hours of April 16, 2011.

That evening Ms Huffman wrote on her Facebook page: "Nakeira Keno.....i hope u got a check for takin the stand...", as well as several insults directed as Ms Keno.

Sarasota Police Department records show Huffman was arrested yesterday and has been charged with retaliating against an informant, victim, or witness.

The Sarasota Herald Tribune reported that she was arrested yesterday as she tried to enter the courtroom where her brother's trial is being held.

According to the newspaper, police said when they questioned her about the Facebook post she told them she was exercising her right to free speech.

In an earlier post on Monday - Tyson's birthday - Huffman posted on her Facebook page: "Just want to send a special shoutout to my lil bro Shawn Tyson happy 17th bday... n even wen it looks like its at its worst just continue to pray god got u luv u bra n he looked soo handsome n court 2day(tears) free em".

The trial has heard that Mr Kouzaris, 24, and Mr Cooper, 25, who were holidaying with Mr Cooper's family, drunkenly walked into The Courts after a night out drinking in central Sarasota.

They were found shirtless, with their trousers round their thighs after being shot several times.

Shawn Tyson, 17, who lived in The Courts, denies two counts of first-degree murder and faces life in prison without parole if convicted.

On Thursday Ms Keno told the court she was driving in the area with some friends when she spotted Mr Kouzaris and Mr Cooper.

She said they had "no shirts, baggy jeans, no shoes".

Ms Keno said she also saw two black men, who "looked young".

"One of them had no shirt and a red bandana over their nose and mouth and a black hat", she said.

She said she then heard gunshots, prompting her to turn her music down. She drove back round past the scene, she said, and saw the two white men on the ground.

Ms Huffman's arrest highlights difficulties police say they faced trying to investigate the murder.

Detective John Todd, lead detective in the case, told the court people did not want to be seen to "rat out" or "snitch" on Tyson.

"This is a very tight group, they were all friends. They all lived in a very tight-knit small community and they were friends," he said.

"These guys don't want to be labelled as a snitch."

Tyson's defence lawyers have said several witnesses changed their stories once they were offered plea deals, or other benefits, by police.

It is claimed two witnesses were given help moving out of the area, while others are said to be testifying in exchange for lesser sentences for other crimes.

The court has not heard any suggestion that Ms Keno was offered any deal or encouragement to give evidence.