The body of a woman who was the long-time mistress of a former Toronto police officer had "two distinct lines" on her neck from a skipping rope, a murder trial in Newmarket has heard.

Det. Rod Fraser, a forensics specialist with the York Regional police, testified yesterday that the rope was wrapped "snug" around the neck of Linda Mariani, about as tight as a man's tie.

It's the theory of the crown that Richard Wills, 50, murdered his lover of nine years because Mariani, 40, refused to leave her husband after he had left his wife. He then stuffed her body into the 60-gallon container in February 2002, and walled up the bin in a crawl space underneath the basement stairs of his Richmond Hill home.

Wills plans to take the stand and tell the six men and six women deciding his fate that Mariani was walking up some stairs to get a Valentine's Day gift when she lost her footing and fell backwards, hitting her head on the ceramic tile floor and dying, defence lawyer Raj Napal told the court earlier.

The retired police officer had a "love pact" with Mariani that they would be buried together, and so he kept the body until he could take her remains to a cottage in Muskoka to bury her, the court heard.

But Wills surrendered to police four months after she vanished.

Detectives found her body in the bin at the foot of the basement stairs. Scuff marks on the floor led back to the crawl space under the stairs where part of a wall had just been taken down, the court has heard.

During cross-examination yesterday by Napal, Fraser denied that he or others at the morgue "re-arranged the rope" around Mariani's neck.

Jurors were shown a series of pictures in which the skipping rope was wrapped tightly around her neck in one picture, and loosely on her chin in others.

Fraser said the rope moved when morgue attendants shifted and unclothed her body in getting it ready for the autopsy.

Prosecutor Jeffrey Pearson told the jurors in his opening address that Mariani had a fractured skull after she was hit on the head with a baseball bat.

Wills then strangled her with a skipping rope, before stuffing her body in the bin, according to the Crown's theory.

In several of the pictures shown to the jurors, Mariani's mouth was wide open after her body was pulled from the barrel. Fraser described the opened mouth as "puckered."

Jurors were shown video of the garage in Wills' house where detectives found seven baseball bats. It's the crown's theory that Wills hit Mariani on the head with a Louisville Slugger, an aluminum bat found in the bin, along with items such as blood-stained men's clothing. The court heard that Wills bought the garbage bin a week before Mariani died. Prosecutor Harold Dale played a video to the court showing officers walking through Wills'messy garage. "How many garbage cans do you count?" asked Dale. "Seven," replied Fraser.

The trial resumes Tuesday and Justice Michelle Fuerst told jurors they will hear the testimony of a woman who died after testifying at the preliminary hearing.