Attorneys for three Somalis charged with murder in the shooting deaths of four Americans aboard a hijacked yacht want a federal judge to stop prosecutors from seeking the death penalty if they're convicted.

The attorneys wrote in a recent court filing that the death penalty's infrequent use makes it arbitrary and unconstitutional.

Ahmed Muse Salad, Abukar Osman Beyle and Shani Nurani Shiekh Abrar face a host of death-penalty eligible charges related to the February, 2011 hijacking of the yacht Quest.

In total, 22 of the 26 counts the defendants are charged with are death-eligible offenses. Their trial is scheduled to begin in 2013 and they have pleaded not guilty.

Prosecutors have not yet responded to the filing. Experts say some of the arguments have been made unsuccessfully in the past.