A Calgary police officer's "abusive" investigation guided by his "tunnel vision" resulted in charges being stayed against a former pastor accused of sexual assault, according to a judge's recently-released written decision, a copy of which has been obtained by CBC News.

Provincial court Judge Harry Van Harten found Det. Steve Harris became convinced of Wagdi Iskander's guilt and his investigation was guided by that bias, according to the 22-page decision.

"The totality of the state conduct here, both because of the loss of and failure to preserve evidence and the abusive nature of the investigation, lead me to conclude that I must denounce that misconduct and preserve the integrity of the justice system," Van Harten said in a written decision which doesn't mince words in detailing the officer's failings.

In April, Van Harten gave a brief, oral decision to stay all charges against Iskander after a pre-trial hearing where the judge agreed with defence lawyer Jennifer Ruttan's argument that Harris displayed negligent conduct.

Iskander, 54, was supposed to go to trial this summer on three charges of sexual assault and one charge of sexual touching stemming from alleged incidents that occurred between 1994 and 2013 involving two underage complainants and one who was in her 20s. 

All of the allegations he faced involved acts of hugging, kissing and touching overtop and underneath clothing.

The Arabic Baptist Church pastor first came onto police radar in 1996 when a 13-year-old boy reported to officers that he'd been inappropriately touched by the pastor over a two-year period. At that time, police decided charges were not warranted and closed the file. 

Nearly 20 years later, the boy's father asked police to re-open the case and Det. Harris became involved. In 2015 Iskander was charged but ultimately, the Crown decided not to pursue the case. 

Harris promised a 'positive result'

Van Harten found that even though Harris described the boy as a "reluctant complainant who was speaking to the police only to placate his parents," the officer was "clearly convinced that the accused was guilty of a criminal offence."

Harris told the boy's parents the investigation would end with a "positive result." Within months, Iskander was arrested and charged again, this time in relation to three complainants.

Two of the three new alleged victims had close connections to the original complainant and the father of the first boy who came forward remained involved. Harris kept that father — who was also a witness — abreast of developments and he had contact with one of the female complainants. 

An internal church disciplinary hearing — which included a CPS officer — had taken place in relation to the third complainant but because of concerns over her "inconsistent version of events," no further steps were taken.

5 videotaped interviews lost

The detective was also criticized for the "unacceptably negligent" loss of five videotaped interviews with witnesses. Upon realizing the evidence was missing, Harris only recreated three of those interviews.

"The interviews that were not reconstructed appear to have been troublesome to Det. Harris' theory of the case," wrote Van Harten.

The judge also noted there was no record of what was discussed in several meetings between Harris and two key witnesses because the detective did not take notes, which police officers are supposed to do.

Further, Harris was found to have tainted potential witnesses by telling them information about others' evidence and the strength of the case.

'I am scared of leaving the house'

In an affidavit filed at the hearing in April, Iskander wrote about how the investigation and charges affected his life. 

"It has caused me to suffer from anxiety," he wrote. "I suffer a panic attack which caused me to cough up blood and resulted in my hospitalization.

"I spend most of my days at home, I am scared of leaving the house."

Iskander was a pastor until 2012. He left Calgary after the 2015 media release announcing charges, which were ultimately stayed by the Crown.

Dustin Paxton connection

This isn't the first time Harris' actions have been questioned in court. The detective was accused of nodding and prompting a key witness at the Dustin Paxton torture trial in 2011.

Paxton was found guilty of brutally assaulting his former roommate and business partner over an 18 month period before dropping him off at hospital.

Harris testified his gestures were done subconsciously and was ultimately cleared by the judge of offering deliberate signals.

The Crown has appealed the judge's decision to stay the charges against Iskander. Prosecutor Matthew Block declined to comment.

Iskander's lawyer said she could not comment as the matter is still before the courts.