INDIANAPOLIS (AP) _ Search warrants served after a fatal house explosion in Indianapolis show investigators pored through computers, cellphone billing records and text messages of three people accused of rigging the blast.
 
  Mark Leonard, his girlfriend, Monserrate Shirley, and his brother, Bob Leonard, are charged with murder and arson in the Nov. 10 explosion. The blast killed a couple living next door to Shirley and forced the demolition of 33 homes. 
 
  Investigators believe the three conspired to fill Shirley’s house with natural gas and programmed a microwave to start on a timer to spark it. The records made public Wednesday say it would have taken about nine hours for enough gas to build up for the blast. 
 
  A phone call went unanswered Wednesday at the office of one of the defense attorneys