SAINT JOHN, N.B. -- Police officers used a washroom outside Richard Oland's office for two days before it was checked and tested by a forensics officer, jurors for the murder trial of Dennis Oland learned Tuesday.

Sgt. Mark Smith of the Saint John Police Force was asked by Crown Prosecutor P.J. Veniot if it concerned him that officers had used the washroom before he could examine it.

"Yes it did," Smith told the court, adding that he continued his search anyway.

Smith said he found a stained piece of paper towel in the garbage that tested positive for possible blood. Swabs used to test the sink in the bathroom also indicated a "presumptive positive" result for blood.

The washroom was located just off the foyer outside Richard Oland's second floor office at 52 Canterbury Street where the body of the 69-year-old businessman was discovered in a pool of blood on July 7, 2011.

His son Dennis, 47, has pleaded not guilty to second-degree murder.

Smith, who collected more than 560 pieces of forensic evidence, was testifying for the fourth day.

During cross-examination, defence lawyer Gary Miller asked Smith if he had instructed other officers on how not to contaminate the crime scene when he left the building on July 7.

Smith said "no."

Miller said one would expect the other officers would know what not to do.

"It would be implied," Smith said.

Earlier in the day, Smith described for the Court of Queen's Bench the search for blood in Dennis Oland's Volkswagen Golf more than a week after the body was discovered.

Smith testified that 11 locations in the car were tested for possible blood using a hemastick on July 14, 2011, but only a few gave weak or very weak indications.

Other tests using chemical sprays to show the presence of blood produced no results at all.

Smith said a red reusable grocery bag was seized from the trunk, along with a number of receipts and other papers from the interior of the car.

For much of the day Smith described his collection of various DNA samples in Richard Oland's office three days after the murder.

He says he found blood spatter almost three metres from where the businessman's body was found, and in some cases almost two metres from the floor.

The court has been told that Oland was killed in a violent outburst that resulted in 40 blows to his head and neck.

Smith was also asked by the Crown about geometric patterns seen in the pool of blood on the floor. He said he initially thought it was left by the footwear of a police officer when the body was moved, but later saw the pattern in pictures of the scene that were taken before the body was removed.

Smith said additional efforts to try to identify the possible footprints were unsuccessful because of "insufficient detail."

The Crown introduced more photos from 52 Canterbury Street, including some of the door to the back alley, that the defence has called a possible exit for the killer.

Smith said the photos of the door and its deadbolt weren't taken until July and August of this year because it had been "overlooked" in 2011.

Earlier in the trial, the court was told that no effort was made to seek fingerprints from the door because police officers had already opened it.

The day ended with the defence showing pictures of blood spatter on the floor, furniture and other items in Oland's office.

"There were hundreds of blood stain spots at the crime scene?" Miller asked Smith, to which Smith answered. "Correct."

"High and low? It appeared to go in every direction?" Miller asked, again getting affirmative responses.

The cross examination continues on Wednesday.