An Ottawa teen on trial for repeatedly dialling 911 to call in fake emergencies was the owner of the Skype account involved in the incidents and the only one who could have placed the calls, Crown lawyers said in their closing arguments Tuesday.

But the lawyer for the now 18-year-old accused says his client was himself set up by other hackers who took over his computer.

The accused was arrested in 2014 when he was 16 years old and faced dozens of charges including public mischief, mischief to property and uttering death threats after at least 30 fake emergencies were called in to police forces across North America, sometimes requiring a SWAT team response.

It's an activity called "swatting," in which 911 calls are made with the aim is to get a large emergency response.

He can't be named due to provisions in the Youth Criminal Justice Act.

Skype, Twitter accounts linked to accused

Crown lawyer Kerry McVey alleged the teen used an anonymous internet phone number to send thousands of dollars worth of pizza deliveries to victims before escalating to bomb threats, fake hostage takings and reports of gunmen on the loose, targeting schools, shopping centres and homes.

During the trial the Crown said the IP address of the Skype account implicated in the hoax calls was assigned to the accused's home, that the thousands of logs for the account were found on his computer, and there was evidence that the computer had accessed the account.

The Crown also brought up evidence presented in court that a Twitter account that bragged about many of the hoaxes and advertised swatting "services" also belonged to the accused and was accessed from his computer.

Defence lawyer Joshua Clarke said the presence of the logs was not itself conclusive evidence, and argued that his client, who had himself been "swatted" in the past, was set up by other hackers, such as the group Anonymous.

Joshua Clarke,Lawyer for accused teen swatter says evidence in court shows client "was set up" <a href="https://t.co/Z70kmgDw1r">pic.twitter.com/Z70kmgDw1r</a> —@JudyTrinhCBC

Clarke said hackers could have either dumped the files on her client's computer or remotely accessed the computer to make the calls.

Crown says defence theory 'implausible'

McVey said the sheer volume of files and activity on the computer makes that theory "implausible."

"No one 'remotely accessed' his computer — over the course of months — to both place these calls and to discuss swatting on an almost constant basis with other Skype users," McVey argued in her submission.

"These actions all occur in the foreground and would have been audible and visible … [to the accused] … a highly skilled computer user alive to issues related to malware and remote access," she wrote.

Lawyers for both sides will return to court on Nov. 3, as Clarke said he plans to argue for a stay of proceedings on the grounds the trial has dragged on for almost two and half years since his client was charged.

Clarke had previously argued over the summer that his client's right to a timely trial was violated, but it was dismissed.

Since that time, however, the Supreme Court has set new guidelines, prompting Clarke to re-argue his case.