Ex-boyfriend busted for stabbing Harlem woman ’50 times’ in ambush, claims she was his ‘entire life’

The deranged ex-boyfriend accused in the vicious ambush murder of his on-again, off-again girlfriend in a Harlem building was charged Tuesday – after whining to cops she had been his “entire life,” cops and sources said.

Luis Marquez, 41, allegedly knifed mother-of-four Carmen Lopez, 47, as many as “50 times” Monday when he attacked her inside her West 129th Street apartment building – where he heartlessly left her to die alone in the hallway, authorities and sources said.

Marquez, of the Bronx, was apparently enraged with jealousy because the victim used him and didn’t make him a “priority,” the sources said.

He described Lopez as his “entire life” to police while in custody though the two were no longer together at the time of the slaying, the sources added.

Building porter Lyron Middleton happened to be cleaning the staircase when he stumbled upon Lopez covered in blood and called 911, he said Monday.

Lopez was rushed to Mount Sinai Morningside Hospital, where she succumbed to her grave injuries, cops said.

Surveillance footage – which Middleton couldn’t bear to watch but only listened to the audio – captured the moment the attacker ambushed Lopez after apparently waiting on the steps for two hours, sources and the porter said.

“She was yelling out someone’s name as it was happening,” Middleton said of the footage. “They say, ‘Luis, Luis, Luis. Luis stop, Luis stop.’”

A woman who identified herself Tuesday as Zoila, Lopez’s sister, refused to talk besides tearful replies of “yes” when asked whether her slain sibling was a good woman, and whether she was hurting.

Another woman who showed up at the building said in Spanish that Lopez was originally from the Dominican Republic.

Marquez’s charges came after he was initially brought to Lincoln Medical Center for a 24-hour psychiatric hold, according to the sources.