"Sometime between the evening of October 13 and October 14, someone had broken into the law offices of Paolo Brocchi and Matteo Palazzoli, in Perugia. A window was smashed with a large stone, and a computer, a cell phone, USB keys, and a printer were missing." (themurderofmeredithkercher.com)
"On the morning of October 27, 2007, the principal of a nursery school in Milan found a stranger coming out of her office. Police were called and the person was identified as Rudy Guede. There were no signs of a break-in; money was missing, but just small change. The police made him open his backpack. Inside the backpack was a computer, a 40 cm kitchen knife (which had come from the nursery school kitchen), a bunch of keys, a small gold woman’s watch, and a small hammer like those found in buses to be used to break windows. Police told the principal that the computer had been stolen from a law office in Perugia.[8]" (themurderofmeredithkercher.com)
"The gold watch is particularly significant because of a possible link to an arson/burglary incident at the residence of one Madu Diaz four days earlier on October 23, 2007 in Perugia. In this incident the residence was extensively damaged by a fire that also killed Ms. Diaz’s cat. Rudy Guede lived next door to Ms. Diaz and was known to her. Although they had greeted each other on an almost daily basis prior to the fire, Guede was conspicuously absent following the fire. Ms. Diaz had had her suspicions about him and when, following the murder, his image was broadcast throughout Europe, she contacted police. Milanese police have never made any effort to determine if the gold watch they found in Guede’s backpack was the same one reported stolen by Madu Diaz. Once again his distinctive M.O. was very much observed at the crime scene: The entry there was through a window, the house was ransacked and he consumed food during the intrusion." (groundreport.com)
"A householder, Tramontano, testified that someone attempted to rob his home, [Date unspecified] and upon being discovered tried to leave. Finding the door locked, the intruder pulled out a jackknife and threatened him. " (themurderofmeredithkercher.com)
Not very clear about the time of day when he broke in - the first was probably the night of the 13th; somewhere I've seen a picture of the grated window he climbed up to break a 2nd floor window. It seems unlikely he'd do that in the daytime.
He was already in the nursery school when the woman arrived in the morning so presumably got in during the night, but they don't know how he got in.