Police say they expect to question a three-year-old boy who might have witnessed the murder of his father in New Westminster, B.C., on Monday.

Nelson Ramirez had stopped to drop off the boy at the home of the child's mother near Cornwall Street and 10th Street when he was shot outside his car with his son still in the back seat.

At some point, police will have to question the boy in the shooting, Cpl. Dale Carr of the Integrated Homicide Investigation Team said Tuesday.

Carr said the shooting appears to have been a targeted attack and was especially outrageous, considering the proximity of the three-year-old.

"I just think it's a callous disregard for the safety of a small child. And I feel the community should be absolutely outraged," he said.

The boy was about three metres away from the spot where his father was killed, Carr said.

Five shots were fired, according to witnesses, and some of the bullets penetrated the white BMW, but the boy was unhurt.

New Westminster, B.C., police sift through debris in a search for clues where a man was shot in front of his three-year-old son Monday night. (CBC)Ramirez, 33, was also known as Nelson Guerrero, Alex Roberto, and Anthony Miranda and had a criminal past, CBC News has learned.

He had been convicted of drug offences in the U.S. and in 2000, was charged in Louisiana with conspiracy, wire fraud, and money laundering in connection to a Canada-based telemarketing scheme.

"Those things certainly are red flags to us and we're looking at whether or not those things have any links [to the killing]," said Carr.

He said investigators will try to determine, "whether or not [Ramirez's] past has come back to haunt him."

The boy is in the custody of his mother, Ramirez's ex-wife.

With files from the CBC's Eric Rankin