A former soccer coach testified Thursday he had no interest in having sex with children and only posed online as a predator to help catch people who abuse kids.

Wesley Vander Leeuw said he didn't know he could be breaking the law when he graphically and repeatedly described planning sexual encounters with children.

The former youth soccer coach and car salesman insisted his words and actions were all done in the name of uncovering other potential offenders.

He spent all day in Edmonton Court of Queen's Bench on Wednesday and Thursday testifying in his own defence.

Vander Leeuw is being tried on five criminal charges, including two counts of making written child pornography and three counts of making arrangements to commit sexual offences against a child.

"Child abuse is wrong," Vander Leeuw told his lawyer during direct examination. "Whether it's physical or sexual abuse."

Thousands of text messages between Vander Leeuw and other adults have been entered as exhibits at the trial.

Court heard he kept a craigslist ad running for more than two years seeking a female or couple "to have some fun" and had online encounters with at least eight individuals, mostly women.

The craigslist ad posted by the accused online. (Court exhibit )

His final encounter was with an undercover Edmonton police officer posing as "Shannon," the mother of an 11-year-old girl.

Most of the online chats were sexual in nature and involved discussions about having sex with children.

"Why are you having these conversations about sex and children?" defence lawyer Shawn King asked.

"To make sure there's not abuse with children," Vander Leeuw replied.

He denied he intended to meet anyone to have sexual contact with a child, insisting the only purpose of arranging meetings was to get a first-hand look at the parent and child to determine if the child had been abused.

Vander Leeuw, 46, testified under oath that he provided graphic sexual descriptions of what he would do with children only to keep the other party talking until they could agree to meet.

"Did you get sexual gratification from these conversations?" his lawyer asked.

"No," Vander Leeuw answered. "Not at all."

'Did I make a correct step?'

Vander Leeuw was grilled all day Thursday by the Crown about his online communications, which were seized and examined by police.

In one case, he repeatedly asked a woman for photos of her daughter. The first picture was a shot of a woman and a girl on a school bus.

Vander Leeuw texted: "Nice. Show me her body."

The woman sent two more photos and the accused allegedly asked her, "Have you taken nudes yet?"

When the woman said no, he responded, "You should."

Crown prosecutor Tara Hayes noted the woman had already made explicit suggestions about arranging sexual encounters for her daughter.

"And you're encouraging this woman to take nude photos of her daughter," Hayes said.

I would be sickened and disgusted if that was my child - Wesley Vander Leeuw

"Did I make a correct step? Probably not," Vander Leeuw said. "I would be sickened and disgusted if that was my child. So I wanted to make sure that wasn't happening."

In another case, Vander Leeuw proposed having sexual contact with a woman and her daughter, including discussions of getting the young girl pregnant.

During cross-examination, he insisted he didn't want to do any of those things, but pretended he did as part of the persona he'd adopted to try to uncover child abuse.

Vander Leeuw agreed with the Crown that many of the things he wrote could be described as "vile, reprehensible and disgusting."

But he told his own lawyer that before he was arrested he had no idea that written child pornography was a Criminal Code offence.

'Doing what I thought was right'

After more than two years of online encounters, it appeared the first time Vander Leeuw actually followed through on a meeting was in January 2017. He thought he would encounter the woman he knew as "Shannon", who was actually an undercover police officer.

He told his lawyer he didn't have a plan when he went to the meeting. Vander Leeuw testified he was going to read body language, look at how they dressed and spoke, search for signs of physical abuse

"There was no one concrete plan because of the variables involved," he testified. "I did what I thought was needed at the time."

"You were encouraging them to share child pornography to see if they were offenders," the Crown suggested.

Vander Leeuw agreed.

"I'm a citizen," he said. "I'm not a police officer. I was simply doing what I thought was right at the time."

Instead of meeting "Shannon" that day, Vander Leeuw was arrested and charged.

The trial is expected to conclude Friday with closing arguments.