The upstate man charged in the heartless cold-case killing of an NYPD detective’s daughter was back on the streets taking his dog for a casual walk after prosecutors botched the case.

Edward Holley, 42, the wheelchair-bound accused killer charged in the heartless 2003 beating death of 20-year-old Megan McDonald, was snapped in Middletown on Monday with his pit bull pup in tow, Fox News said in a report.

Holley was paralyzed from the waist down in a 2007 car wreck.

Holley, who was McDonald’s estranged boyfriend at the time, was arrested by New York state troopers last month and charged with murder in the March 14, 2003 killing.

Investigators said eye-witness accounts and surveillance video evidence helped link Holley to the crime two decades later.

McDonald sought out Holley to buy marijuana just hours before she was killed while sitting in her 1991 Mercury Sable, cops said.

Holley was arrested on April 20, arraigned on murder charges in an Orange County courtroom, and ordered held without bail.

But the case hit a serious snag on Wednesday when Orange County Judge Peter Green ordered Holley released because prosecutors didn’t get a grand jury indictment in time.

Under state law, a defendant cannot be held in jail if DAs are unable to secure an indictment within a strict timeline — forcing the judge to let Holley go while the case is still pending.

Red-faced prosecutors have since turned the case over to a special prosecutor.

McDonald, a college coed at the time of her death, was the daughter of former NYPD detective Dennis McDonald, who died a year before she was killed.

In a statement after Holley was released without bail, the slain woman’s family said they were “disappointed” by the unexpected development in the case.

“Since Megan was brutally taken from us we have been advocating for the arrest of the person responsible for her murder,” they said. “After patiently waiting for over 20 years we are confident that the police have arrested the right person — Edward Holley.

“The process may not be easy or follow our preferred path,” the family said. “But we will not rest until justice is secured for Megan.”

John Beatty, the family’s attorney, added that while Holley’s release was “disheartening,” the family knew of it in advance and was “already aware of this phase of the criminal justice process.”

Meanwhile, Holley is free to go about his business — and let his dog go about his.