TORONTO -- A Toronto-area constable charged in a corruption investigation didn't intend to act dishonestly and simply lacked training on certain police procedures, his lawyers argued Friday.

In closing submissions, defence lawyers for Richard Senior also argued that none of the incidents that led to his charges would have occurred without the "instigation" of police, who were secretly investigating him in the lead-up to his arrest.

"As a result, there is a clear lack of intent with respect to Mr. Senior," lawyer John Struthers told a virtual court.

Senior, a longtime officer with York Regional Police, has pleaded not guilty to 14 charges, including breach of trust and trafficking cocaine and steroids.

He was arrested as part of a broader corruption probe in October 2018 and initially charged with 30 offences, but the remaining 16 charges were withdrawn as the trial began last month.

The Crown alleges, among other things, that Senior, 46, filed an intelligence report about his former mistress and falsely claimed the information came from an informant, when in fact he had his friend sign the report under an alias.

Prosecutors also allege the constable planned to rob a fictitious drug warehouse after hearing about it from an undercover officer who was posing as an informant.

They further allege Senior offered to sell the drugs from that warehouse to two men he knew, and sold steroids to another undercover officer; that he stole money he was given to pay informants; and that he inappropriately accessed a police database and disclosed confidential information.

Struthers said Friday that many of his client's actions, particularly in regards to his interactions with the undercover officer posing as an informant, were due to his lack of experience and training with such matters.

Senior was "untrained sent off into the field" and made decisions to assist someone he thought was a great informant and who had provided useful information on drugs and guns, the defence lawyer said.

The officer particularly didn't know what to do if an informant refused or "abandoned" the payment, as happened in one instance where the undercover officer posing as an informant returned a $1,000 payment shortly after receiving it, the lawyer said.

"So we put him into this position, with this money he didn't ask for, didn't request and didn't want, we give him documents he hasn't used before with instructions he hasn't been given," Struthers said.

"We send him off to do this, and then if he fails to do this administratively properly in some way, he's a criminal."

As for the report on his former mistress, Senior mistakenly believed he could himself act as a confidential informant and provide that information without revealing his identity, the defence lawyer said. There is also no evidence of what happened to the $300 Senior was given to pay that source, the lawyer said.

When it comes to the warehouse robbery, the plan had not progressed beyond preparation at the time of Senior's arrest, Struthers argued. What's more, Senior could not have made serious offers to "offload" cocaine from the warehouse because he wasn't sure what he would find there, the lawyer said.

As for the steroids, Senior merely assisted two officers -- one of them an undercover officer -- in purchasing the drugs, but wasn't trying to facilitate the sale, Struthers argued.

In his closing submissions Friday, prosecutor Peter Scrutton said there is "overwhelming" evidence that Senior intended to act dishonestly, pointing to recordings of conversations the officer had with an undercover officer about some of the incidents.

In one instance, Senior can be heard saying he will return a payment to York police if the undercover officer doesn't accept it, which suggests he knew the money belonged to the force and should be returned if it wasn't paid out, Scrutton said.

On a second occasion, Senior put the money in the cupholder of a car but didn't even offer it to the fake informant, the prosecutor said. He nonetheless submitted a receipt signed by the undercover officer, Scrutton said.

"Not stealing, not lying, not doing crime... with a confidential informant is not the stuff you need specialized training to know that you're not permitted to do," he said.

Even if there was "virtue testing" at the hands of police, "Mr. Senior failed every single test," Scrutton said.

The planned warehouse robbery was "well past preparatory," given that on the day Senior believes the drugs to be arriving, "he steals a shotgun to rob the warehouse," the prosecutor said.

The officer is also heard on recordings offering a friend a half-kilo of cocaine for helping with the robbery, which fits the definition of trafficking, Scrutton said.

Senior also trafficked in steroids because, were it not for him, "the sale would not, could not, have occurred," the Crown lawyer said.

"He has not just put the buyer and the seller together...he's coming in between them and he's actually arranging the deal" between two parties that didn't previously know each other, he said.

A verdict in the case is expected April 21.

This report by The Canadian Press was first published Feb. 19, 2021.