For those who are quite reasonably wondering why the cops never searched for evidence at Lumumba's place, let me suggest a simple answer: they didn't do it because they knew that they wouldn't find anything.
Let me explain. There is no evidence of a search of Lumumba's residence, and they never analyzed any of his personal effects in the lab. There is just one Lumumba sample identified in the lab records and that is Lumumba's reference sample, no. 47232 (cheek swab, I assume). This was seized and processed on November 6, 2007. Also processed at this time were the vaginal swab (47081) and the feces sample (nos. 47220-222).
The lab identified the vaginal swab and feces sample results as belonging to an unknown man, who it designated "Uomo 2". By comparing the Lumumba reference profile and the Uomo 2 profiles, the prosecution knew almost immediately (probably the evening of November 6) that Lumumba was NOT the perpetrator.
Thus, we know that the cops did not search Lumumba's residence because (i) there is no record of or samples from such a search, and (ii) the cops would have had no reason to do such a search, since they knew that Lumumba wasn't the perp and therefore they would find nothing.
Now the questions become: why was Lumumba kept in jail? When and why did Mignini interview Patrick? When and why was he charged? What evidence was offered against him?