A former St. Thomas police constable who pleaded guilty to sexual interference was sentenced to 30 months in prison Friday.

Garry Christiansen's sentence will also be followed by three years' probation.

The sexual interference was in connection with his relationship with a then 15-year-old girl.

In an agreed statement of facts, the court heard last June the then 53-year-old initiated a relationship with a 15-year-old girl who had come in to the police station for a police background check.

After exchanging text messages, they reportedly began a 17-month long consensual sexual relationship that was kept secret.

They would meet at the officer's home, and while the encounters did not initialy involve intercourse, that reportedly changed once the girl turned 16.

The agreed statement of facts also revealed that Christiansen told the victim, "He was afraid of going to jail if she told anyone about their relationship."

Christiansen was arrested in Oct. 2017 after a Crime Stoppers tip the month before prompted St. Thomas police to involve Ontario's Special Investigations Unit.

In a statement Friday, St. Thomas police Chief Chris Herridge said everyone regarless of position will be held accountable for criminal actions.

"We understand the negative perception this incident may have created. It is disheartening for our members and we want to assure the community that this is not a reflection of the men and women of the St. Thomas Police Service who work so hard every day to uphold the law and keep our community safe," he said.

Herridge also said his thoughts are with the victim and her family "throughout this long and arduous judicial process."