Decades old murder solved

In 1981, a 6-year old boy was decapitated in Hollywood Florida. The little boy, Adam Walsh, was abducted from a shopping center, then murdered. Adam's abduction lead to the tv show America's Most Wanted, hosted by his father John Walsh. The suspect, Ottis Toole had apparently confessed twice to killing the boy, but then took his confessions back. Toole also confessed to hundreds of other murders, but most were lies. The authorites made sevral mistakes in this investigation, including losing blood stained carpet from Toole's car, and overlooking the fact that a sandal and green shorts similar to what Adam had been wearing had been found in Toole's house. Adam's head was discovered in a canal 120 miles away, but the rest of his body was never found. So this closes more than two decades of unhapiness and torture for Adam's parents. The suspect has been dead for awhile.

It's great that this case was finally solved, though it should've been solved alot earlier. My questions are why on earth would someone abduct a random little boy and decapitate him, and confess to hundreds of murders they didn't do?