LT. JONATHAN D. Josey II spent nearly two decades building a career as a decorated police officer. But with his split-second takedown of a woman captured on video Sunday, he tore it all down.

Police Commissioner Charles Ramsey announced Wednesday that, effective Thursday, Josey, 40, a 19-year veteran Highway Patrolman, will lose his job.

Technically, he'll be suspended for 30 days with intent to dismiss, for his now-infamous punching of Aida Guzman, 39, during a celebration Sunday at 5th Street and Lehigh Avenue after the city's annual Puerto Rican Day Parade.

"I watched the video over and over again, and I also listened to the interviews the complainant gave the media," Ramsey said. "Looking at everything, it was my sense that this was a very serious violation of department policy and that the force used was not the force necessary to effect an arrest."

He said his decision to ax Josey - who ran a violence-prevention program in his spare time and was cited by the Citizens Crime Commission of Delaware Valley for bravery in 2010 after interrupting an armed robbery and shooting the perpetrator - was difficult.

"He has served for a long time and he's done a lot of outstanding things," the commissioner said. "But this is a violation of trust and abuse of authority, and it cannot be ignored."

Meanwhile, in a statement released Wednesday, the District Attorney's Office said it intends to withdraw the disorderly conduct charge filed against Guzman when Josey arrested her Sunday.

In a video of the incident, it appears that Josey and a group of other officers turn around in response to someone throwing liquid at their backs. Guzman didn't throw the liquid, but can be seen waving what looks like a can of "silly string."

Josey catches up to Guzman as she walks away and punches her in the face, knocking her to the ground before handcuffing her.

"I expected from Day 1 that the charges would be dropped," said Guzman's attorney, Enrique Latoison. "She's relieved. She's just happy this part of the nightmare is over."

He said Guzman hasn't decided whether she wants to sue the city over the incident, which left her with a fat lip, cuts to her arm and hand, and head and neck pain.

"She does have some medical bills that she's incurred as a result . . . but we haven't made the decision to actually file suit," Latoison said. "I will say, however, we do feel like an apology is still outstanding in this matter."

John McNesby, president of the Fraternal Order of Police Lodge 5, called Ramsey's decision to terminate Josey a "bad move."

"It's a ready-fire-aim approach. The investigation's not even complete, the ink's not even dry, and they're gonna fire him?" McNesby asked. "It sends a bad message to cops on the street: 'Be careful out there, because the city may not have your back.' "

The incident involving Josey was the latest in a string of recent controversies that have befallen the Police Department, after the Daily News last week reported on several sexual-harassment lawsuits against 17th District Capt. Anthony Washington, and after Ramsey in August commissioned an independent firm to investigate sexual-harassment allegations against former Internal Affairs Staff Inspector Jerrold Bates. In August, Ramsey also suspended and transferred Northwest Police Division Inspector Aaron Horne and 35th District Capt. John McCloskey amid turmoil over their alleged coverup of an arrest.

Ramsey said the police supervisors involved in other recent scandals haven't met as severe a fate as Josey because those cases have investigations pending or remain under review.

"The real tragedy is that it overshadows the solid supervision and leadership that takes place in the department every single day," Ramsey said. "It really does a disservice to the men and women that work hard every day and do their jobs properly."