Sigh ... the reporter wasn't yet on first name terms with Eddie and Keela ... but it is obvious which the spaniel with the ability to smell blood on knives which have been washed clean is ... and she is CSI.
They looked for evidence of blood in the apartment and didn't find any on 4 May 2007.
"There proceeded the search for possible blood traces in all of the apartment, using a variable- wave light source appropriate for the task.This search resulted in the detection of several spots having a red-brown tone that suggested blood, which were subjected to a "Kastle-Mayer" peroxidise test, the result obtained, in all cases, being negative.
There also proceeded the observation and search for blood traces inside the apartment using a chemical product to find latent blood traces. In the application of the referred product no results characteristic of the presence of blood traces were found."
https://www.mccannpjfiles.co.uk/PJ/5A_FORENSIC_4_5_7.htm