LECCE - The former flat mate of the couple found stabbed to death last week in Lecce has allegedly confessed to their murder saying he killed them because they were “too happy,” police sources said on Tuesday.

 Police arrested Antonio De Marco, 21, a student from Casarano, a town in the Lecce area, on Monday evening.

 Serie B referee Daniele De Santis, 33, and his fiancée Eleonora Manta, 30, a law graduate who had recently started a job at INPS, were murdered in their home in Lecce on Sept. 21.

 Police ruled out ‘crime of passion’ as a motive but said given the suspect had few friends and his introverted, withdrawn nature, he would have been bothered by the couple’s apparent happiness.

 "I did a stupid thing, I know I was wrong,” De Marco told investigators.

 “I killed them because they were too happy and that’s why I got angry.”

 Lecce prosecutor Leonardo Leone De Castris said the murder was premeditated and had been planned to the smallest detail.

 At the murder scene, investigators found two bottles of bleach, cable ties and all the equipment required to clean the crime scene so as not to leave a trace.

 During the attack, De Marco dropped notes containing a map, instructions on how to avoid the security cameras, and the “prodromal activities” that should take place in the lead up to the murder.

 The notes revealed his plans to tie the couple up and torture and kill them, investigators said. After stabbing them to death De Marco had planned to scrub the site with detergent and leave a message on the wall for the city.

 For one year, De Marco had rented a room in the same house as De Santis but in the last two months of his tenancy, De Santis’ girlfriend had also been living in the apartment.

 The couple is believed to have let the suspect in while they were having dinner.

 Witnesses had told police a man dressed in black with a yellow backpack had run away from the scene holding a knife.

 The alleged murderer was identified from security camera images, wiretapping and a graphic report on the bloodstained notes that were lost during his escape.

 cc