Police found murdered teenager Louise de Waal's school bag on Johannes Jacobus Steyn's property, the High Court sitting in the Palm Ridge Magistrate's Court in Alberton, heard on Tuesday.
"I opened the black bag and inside I found a pink and grey school bag. On it were stickers with the name Louise de Waal," Warrant Officer Danie Pieterse testified.
Steyn, who is being called the "Sunday rapist", is accused of 37 counts, including the murders of De Waal and another schoolgirl, 14-year-old Lazanne Farmer.
Pieterse told the court he was instructed to visit Steyn's house to look for a silver bakkie, which he found. However he could not enter the property because the gate was closed.
He entered only when a tenant, Hermanus Mulder, arrived and opened the gate for him.
Pieterse searched the back of Steyn's bakkie and in it found the black bin bag containing De Waal's school bag and a cellphone cover.
Asked whether the bags could have been thrown over the fence, he said this was unlikely as they were placed too precisely.
"All three were precisely in a row next to each other on the bakkie."
Warrant Officer Paul Fern testified that he also saw the school bag in the bin bag and that he identified De Waal's belly ring.
He was asked by Judge Sita Kolbe why he decided to search Steyn's house in Wilro Park, Roodepoort.
"He could possibly have been the Sunday rapist, and on those grounds it was alleged that he kept certain trophies from his victims," Fern said.
Steyn, 36, pleaded not guilty on Monday to the 37 charges against him, which include 11 counts of rape, 10 of sexual assault, 10 of kidnapping, one of attempted sexual assault, one of attempted kidnapping, and two of assault.
The 11 girls he allegedly attacked between 2008 and 2011 in Gauteng and the North West were aged between 11 and 18.
Steyn allegedly abducted De Waal in Roodepoort in October last year while she was on her way to school.
Her burnt body was found on a Magaliesberg farm later the same day.
Steyn handed himself over at the Margate police station in KwaZulu-Natal the next day.
On Monday De Waal's mother, Shereen, was asked to identify the contents of her daughter's school bag.
A friend of the teenager tearfully testified how the death had changed her life.