The lawyers for accused letter bomber Guido Amsel were in court Monday challenging the information police used to obtain a warrant to get a DNA sample from their client.

Amsel is facing multiple counts of attempted murder and explosives-related charges after letter bombs were sent to his ex-wife and two Winnipeg law firms in July 2015. One of the bombs detonated, seriously injuring lawyer Maria Mitousis.

The actual trial doesn’t start until next month, however court set aside time to hear pretrial motions.

Defence lawyer Jeremy Kostiuk told that the court investigators and police officers who prepared the information to obtain the warrant should be called for cross-examination to answer questions about the exclusion of key information.

Part of the issue surrounds swabs that were taken from Amsel’s hands in July 2015.

Kostiuk told court an initial test detected the presence of an explosive substance on Amsel’s hands.  He told court one officer had received information indicating a second lab test, which ultimately came back negative, was required to confirm the findings of the initial test.

Kostiuk said that information wasn’t properly communicated between investigators and their superiors.

“The statement that swabs tested positive for HMTD (homemade explosives) is at the same time true and deceptive,” Kostiuk told court. “The only conclusion that can be drawn is that presumptive testing cannot be used as evidence.”

Kostiuk told court that investigators should be required to answer questions to determine if it was “a good-faith accident, or negligence, or deceit.”

The Crown told court there’s no point allowing cross-examination, because the officer who prepared the application for the warrant wouldn’t have known about the existence of the report.

“This isn’t a situation where there’s any evidence he knew or ought to have known about the existence of that report,” Crown attorney Chris Vanderhooft told court. “The positive test on the scanner (the first test) is still a positive test.”

“The affiant spoke to numerous investigators and consulted numerous sources in preparing this affidavit.”

On the issue of defence lawyers requesting to cross-examine other investigating officers who contributed information for the warrant application, Vanderhooft told court: “That’s nothing more than a fishing expedition.”

Amsel, who remains in custody, was also in court wearing a headset to make it easier for him to hear the proceedings.

Amsel has pleaded not guilty to all charges and will be tried by judge alone in provincial court in October.

The trial will deal with all charges pending against Amsel.