HALIFAX - Police have made an arrest in a four-and-a-half-year-old murder case involving the death of a Halifax teacher.

The body of Paula Gallant, 36, was found in the trunk of her car in December 2005.

"No charges have been laid. The investigation is still ongoing, so we can't release his name," RCMP Cpl. Joe Taplin said Tuesday.

Taplin said the joint investigation, involving the Mounties and Halifax police, took a lot of effort.

"It's been a very intensive and extensive investigation involving a lot of dedicated members that kept working at this file," he said.

Gallant's vehicle was found outside the Beechville Lakeside Timberlea elementary school where she had taught since 1999.

The married mother of one had left home in her car to go shopping earlier in the day.