A 20-year-old man has been charged with the March killing of a woman in her car when she met him to sell a cell phone, authorities said.

Marvin Coleman Jr. was arrested following a traffic stop and charged with murder and weapons offenses, the Burlington County Prosecutor’s Office announced Tuesday afternoon.

The charges stem from a March 6 shooting in Willingboro that killed Maribely Lopez, 21, of Lindenwold.

The prosecutor’s office said Coleman arranged to meet Lopez in front of an empty house on Medley Lane via OfferUp, an app for selling used items.

Instead, Coleman killed Lopez with a single shot to the head through a the partially open driver’s side window, the prosecutor;s office alleged. She was found the next morning, the car still running. Authorities believe she had been dead in the car for more than nine hours.

Investigators found the advertised phone inside her car, but the motive in the shooting is not yet clear.

Lopez was a graduate of Lindenwold Highschool who loved sports, particularly basketball and soccer. She left behind her parents and two brothers, according to her obituary.

“The evidence points to this murder occurring during a planned OfferUp transaction,” Prosecutor Scott Coffina said in a statement. “People selling items online to strangers should exercise appropriate caution, such as utilizing safe transaction zones that many of our local police departments maintain in the parking lots of their stations.”

This isn’t the first such murder in New Jersey. Last year, 20-year-old Danny Diaz-Delgado was lured into a Trenton alley, tied up and killed when he met strangers to buy a Playstation for his little brother. A man in Ocean County trying to buy an iPhone was robbed at knifepoint, others in North Jersey became carjacking victims and one in Bayonne robbed at gunpoint.

Like Coffina, police have urged those using the apps or social media sites to purchase items to meet in safe, designated spaces, like police station parking lots. Some have video surveillance and signage for security, by NJ Advance Media reported last year that Trenton, New Brunswick, Paterson and Elizabeth all lacked security cameras.

At the time, at least 20 New Jersey police departments were using and promoting the program, but all were in smaller, suburban areas, aside from an exchange zone in Camden.

Amanda Hoover can be reached at ahoover@njadvancemedia.com. Follow her on Twitter @amandahoovernj. Find NJ.com on Facebook.

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