A Manitoba judge hearing the case of accused letter bomber Guido Amsel has dismissed a defence motion to quash a DNA warrant used to secure a blood sample.

In a decision delivered Friday morning in a Winnipeg provincial court, Judge Tracey Lord ruled there was no basis to toss out the warrant.

Amsel, 51, is charged with five counts of attempted murder and several explosives offences.

His lawyer Sahell Zamen said the decision on the motion will not significantly change how the defence will fight the case.

"There is a trial that has to be adjudicated and lots of disclosure," Zamen said. "There will be lots of cross-examination ... We still have some arguments to advance with this particular matter and we intend to do that."

Amsel was arrested in July 2015 after letter bombs were delivered to his ex-wife and two law firms. Two of the bombs were safely detonated, but lawyer Maria Mitousis lost her right hand and suffered several other injuries when a package she was holding exploded.

Defence lawyers argued a police officer who swore an affidavit in the DNA warrant and a number of "sub-affiants" failed to provide relevant information regarding swabs taken from Amsel's hands to test for explosive residue, and an FBI handwriting analysis.

Motion revolved around a 'presumptive positive' explosives test

Court heard an initial swab test of Amsel's hands yielded a presumptive positive result for explosive residue. A subsequent test at the RCMP lab, which was not noted in the police affidavit, could not confirm the presence of explosive residue.

Amsel's defence lawyers argued the exclusion of the report and other relevant information could be evidence of an attempt to deceive the court.

Winnipeg Fire Fighters

Winnipeg police investigated the site of an explosion at the Petersen King law office. (Erin Brohman/CBC)

Lord said she was satisfied the Winnipeg Police Service officer who prepared the warrant and an "information to obtain" document included all relevant information available at the time it was executed, Aug. 27, 2015.

"I am satisfied he was diligent in his preparation of the information to obtain and discharged his duty ... to make full, fair and frank disclosure of relevant evidence known to him at the time," Lord said. 

"I do not accept that he acted in bad faith by deliberately failing to make inquiries about the outstanding report in order to create a situation of plausible deniability." 

The trial will hear testimony from its first witness Oct. 24

Amsel is also facing charges in connection with a 2013 explosion at his ex-wife's home. No one was injured in that incident.