Security has been tightened for the trial of Richard Ramirez, accused of 13 satanic slayings in the "Night Stalker" serial murder case that terrorized California four years ago.

Deputy District Attorney Philip Halpin was to give the prosecution's opening statement Monday, six months after jury selection began.Superior Court Judge Michael Tynan told the 12-member jury to anticipate two years of testimony.

When the courtroom opens, spectators will have to pass through metal detectors, similar to the devices used in airports. Ramirez will be restrained by leg shackles in court.

Halpin requested extra security measures last August when the Sheriff's Department informed him Ramirez had allegedly threatened to kill him in court with a smuggled gun and then turn it on spectators.