The provincial Justice department said Tuesday it has decided there is no legal basis for an appeal in the case of Harry Bakema.
He was found not guilty last month of deliberately botching an investigation into a deadly car crash in order to protect another officer.
Bakema, 62, faced charges of obstruction, perjury and breach of trust in his handling of the crash that killed Crystal Taman.
Taman's widower, Robert Taman, said Tuesday he was disappointed but not surprised by the Crown's decision.
"I've been disappointed through this whole thing ... the prosecution didn't fight hard enough," Taman said.
"I feel it was absolutely obvious that there was a coverup."
Bakema was the police chief in East St. Paul, a bedroom community north of Winnipeg, when a compact car driven by Taman was stopped at a red light on the morning of Feb. 25, 2005.
Behind her came a pickup truck driven by Derek Harvey-Zenk, an off-duty Winnipeg officer who had been out all night partying with colleagues.
Despite clear road conditions, a large warning sign and a flashing light that alerts drivers to the intersection, Harvey-Zenk made no effort to stop and plowed into the back of Taman's car.
Bakema, who had worked with Harvey-Zenk in Winnipeg, was among the first officers on the scene. Instead of testing Harvey-Zenk for impairment or asking him whether he had been drinking, Bakema helped Harvey-Zenk walk to a police vehicle and had him sit inside.
Due to a lack of evidence, impaired driving charges were dropped and Harvey-Zenk was given a two-year conditional sentence of house arrest for dangerous driving causing death.
A 2008 inquiry into the case led to Bakema's arrest and the disbanding of the East St. Paul police force.
Last month, provincial court Judge Kelly Moar ruled that while Bakema's investigation was seriously flawed, the Crown did not prove that he had any criminal intent. Bakema and his small police force appeared to be underequipped and overwhelmed by the crash, Moar said.
Taman has called for tougher laws for suspected drunk drivers, as well as better civilian oversight of police.
"I think the changes are going to come, it's just that they're slow in coming."
Bakema is no longer a police officer. He became a real estate agent after the crash.