With Bernardo, police had his DNA long before he was arrested, but they were backlogged with DNA testing for the Scarborough rapist. That was a mistake. Police then made a deal with Homolka with the condition that she tell the truth. She lied, but police upheld their end of the deal anyway. With Russell Williams, police endowed him with some sort of special status when the investigation led to his doorstep. Williams pointed the finger at a neighbour and police investigated that neighbour. It was when Williams went through a check stop and his tires matched those in a field next to a crime scene that one of the officers decided that, regardless of Williams' special status, they would look into it. With Robert Pickton, police knew that he had handcuffed and assaulted a woman at his farm, but because she was a prostitute, they did nothing. Because it was prostitutes that were vanishing, police did nothing. They made huge errors. Police also made huge errors with Clifford Olsen. Because the abductions and murders were in different jurisdictions, and because police were immature and territorial about their cases, Olsen murdered eleven children before an arrest. Police then went on to make a cash for victims deal where Olsen's wife received $10,000 for each murdered child.
With Garland, police did not drop the ball. They pursued several avenues of investigation, zeroed in on video surveillance footage, discovered the old Ford truck in pristine condition, located the owner, and made an arrest as soon as possible for, what I would consider, a minor infraction: false identity documents. That was four days after the murders. They held him as long as possible ... something like eight days ... to buy themselves time to complete the DNA testing. As soon as the testing was completed, they re-arrested him and charged him with the murders. 15 days from murders to arrest reflects excellent police work.
