The Arkansas Supreme Court has reversed a murder conviction because a juror tweeted and another slept during the trial.

Erickson Dimas-Martinez was sent to death row for robbing and killing 17-year-old Derrick Jefferson, after a party in northwest Arkansas in 2006.

The attorneys for Dimas-Martinez had appealed against his 2010 murder conviction stating that a juror sent tweets despite clear instructions from the judge not to do so; jurors had been instructed to not speak over mobile phones or tweet about the case and its proceedings.

However, Randy Franco, a juror, tweeted in between trial proceedings. One of his tweets read: Choices to be made. Hearts to be broken... We each define the great line. The juror also tweeted: all done an hour before the final verdict was read. The juror's tweet resulted in public debates on the issue.

The juror's misconduct was brought to the notice of the trial judge by the attorneys for Dimas-Martinez and, following an interaction with the concerned juror, the judge declared herself satisfied with the explanation.

However, the Supreme Court later reversed the conviction order and said Dimas-Martinez deserved a new trial. The court said the juror's behavior amounted to misconduct and violation of court rules.

The court also asked a panel to examine whether jurors' access to mobile phones during trials needed to be limited.