A DIGITAL forensic expert in the Molemo "Jub Jub" Maarohanye murder trial told the Protea Magistrate's Court yesterday that the police used flawed investigation methodology and compromised the integrity of a video shown to the court of an alleged drag race.

Maarohanye and co-accused Themba Tshabalala are on trial on four counts of murder, two of attempted murder, reckless and negligent driving, and driving under the influence.

The pair are alleged to have been drag racing their Mini Coopers on Mdlalose Street between Protea Glen and Protea North in March 2010 while drunk and high when they crashed their Mini Coopers into six school children.

But under cross-examination from Tshabalala's attorney, Riana Smalberger outlined methodology that should be used in collecting evidence and how electronic evidence should be handled.

"The evidence was compromised (it is not acceptable to have the video as evidence) as it is not of a forensic sound manner," said Smalberger.

She said the police should never have allowed the witness who shot the video to delete other footage before handing in her phone as evidence because it affects the quality of the remaining material.

Maarohanye's defence attorney Ike Motloung succeeded in convincing the court to accept a docket of a senior prosecutor at the court arrested in an unrelated matter. The prosecutor had handled a four-second DVD of the video of the drag race just before it disappeared in court.

The trial continues on July 13.