St. Cloud, MN (Learfield Wire Service)  -- Six search warrants involving the abduction and murder of Jacob Wetterling in 1989 were unsealed on Friday.

Among other things, they explained why Saint Joseph area farmer Dan Rassier was identified as a person of interest in the 11-year-old boy's disappearance. The documents indicated Patty Wetterling wore a recording device in 2009 to try and draw information from Rassier for investigators to consider -- and the warrants outlined what officers were looking for, including a handgun and Jacob's remains -- when officers dug up parts of Rassler's farm before deciding he was not the man they were looking for.

The documents were made public after Danny Heinrich led officers to Jacob's remains last weekend before he pleaded guilty this week to charges not directly related to the Wetterling kidnapping, and then told a judge how and why he kidnapped and killed Jacob.