The 45-year-old father of three from the nearby town of Schwalmtal, North Rhine-Westphalia abducted the boy on September 3, 2010, sexually assaulting and killing him the same day, investigators said.
During “protracted and comprehensive” questioning, Olaf H. admitted that on the evening of the crime he had driven around aimlessly after his boss had “dressed him down,” lead investigator Ingo Thiel said.
During the drive he encountered Mirco, who was riding his bike to his home in Grefrath from a skate park.
Olaf H., who works for Deutsche Telekom in Bonn, reportedly persuaded the boy to get in his car. He then threw the bike in a ditch and drove to a wooded area near Grefrath where he assaulted and killed the boy. He left the body at the crime scene, investigators said.
According to Thiel, police found the body where the suspect said it would be some six kilometres from an area police had searched several times.
“Mirco was absolutely a victim of chance,” Thiel said.
The suspect, who lives with his third wife, apparently did not awaken any suspicions among his family or neighbours when he returned after tossing Mirco's clothing and mobile phone out on his way home.
“He was thought of as a family man. His hobby is gardening,” Thiel said, adding that the suspect also admitted to having driven around aimlessly in the same fashion at least once before, but had no previous convictions.
“One could assume that he was a time bomb.”
Thiel did not say how the boy was killed, but said the crime had been about power, violence and an “act of degradation.”
Police were led to Olaf H. by a witness who reported seeing a dark VW Passat wagon around the time of the boy's abduction in the area.
But with some 150,000 such car models in Germany, it took investigators some time before they found the right vehicle - a leased company car that Olaf H. had turned in when the contract ran out in November.
From there it was taken out of service to be sold abroad, and travelled on what investigators called “an odyssey.” It was even almost sold to a customer in Russia before “technical methods” led police to find it with a man in Luxembourg, who allowed them to examine it on January 24.
“We had so much on Olaf H. that we also would have gone to Russia to get it,” Thiel said.
By the time police found the vehicle they had already scoured another 1,500 cars and had another 2,000 in their sights.
DNA taken in a saliva sample and fibres from Mirco's clothing in the car connected the suspect to the crime, and he was arrested at 6 am on Wednesday. He confessed shortly thereafter.
Police launched one of their largest search actions in German history after Mirco went missing, employing 1,000 officers, a Tornado jet and a drone. But they failed to find his body because it was outside the search perimeter. Had they been in the right area, the Tornado jet's heat sensors would have certainly found the body, Thiel said.
Olaf H. faces charges of murder, kidnapping and sexual assault on a child, Krefeld state prosecutor Silke Naumann said.