Calgary police officer Const. Trevor Lindsay has been convicted of aggravated assault connected to a violent arrest in 2015 that saw a handcuffed suspect suffer alleged brain damage.

Lindsay, 30, had testified he struck the suspect three times because he was “worried about biting, head-butting, kicking, spitting, knee strikes from him.”

Lindsay also testified he was worried about the transmission of communicable disease if the suspect spit on him and his partner.

In his written decision, Justice M.J. Lema rejected that, saying he found the level of force used by the officer “unnecessary and excessive.”

Daniel Haworth was arrested May 25, 2015, following an investigation into a break-in at his ex-girlfriend’s home.

A surveillance camera captured an officer escorting Haworth from a police vehicle to the arrest processing unit. The officer, identified as Lindsay, appears to punch a handcuffed Haworth from behind three times before throwing him headfirst to the ground.

Lema’s decision says Haworth did spit blood, but that it was onto the door and window of the police cruiser and not directed toward Lindsay or his partner. The decision adds Haworth spitting was warranted as it happened after being punched by Lindsay, which caused his mouth to bleed.

In 2017, Haworth’s brother Robert told CTV that Daniel Haworth, who had died months earlier from a drug overdose, was an addict but not deserving of the treatment he received while in custody.

According to his family, Haworth was transported to hospital following the 2015 arrest where he was diagnosed with a permanent brain injury. His symptoms included memory loss and numbness.

Lindsay is scheduled to return to court July 4 for a sentencing hearing.