UPPER WEST SIDE, Manhattan (PIX11) — A second person is being sought by police in connection to the murder of a 74-year-old woman found bound and gagged inside her Upper West Side apartment, according to authorities.

Lashawn Mackey, 47, has already been charged by prosecutors with murder and burglary in the death of Maria Hernandez, officials said. But now, investigators say they’re also looking for a second person who was seen with Mackey both inside and leaving Hernandez’s apartment building. The unidentified person, who’s pictured in a surveillance photo released by police, was additionally seen with Mackey around Manhattan and Brooklyn, authorities said.

Hernandez was found by her sister lying unresponsive on the floor of her apartment on West 83rd Street near Columbus Avenue around 9:55 p.m. Jan. 18, police sources previously told PIX11 News. Hernandez was bound at the hands and feet, and covered in a sheet, sources said. She had multiple bruises and fractures, and her death was ruled a homicide by asphyxia, officials said.

Hernandez’s sister, who lives in a different unit in the same building, found the victim just hours after they’d returned home from seeing a show together, sources said. When Hernandez’s daughter couldn’t get in touch with her, she asked her aunt to check in, leading to the grim discovery, sources said.

Investigators, who believed that the slaying may have resulted from a robbery gone wrong, found that the security system in the superintendent’s office had had its cables cut and was missing its DVD, sources said.

Despite the apparent attempts at covering up the incident, police arrested Mackey, of Brooklyn, on Saturday. 

“I’m innocent. This is not how you do justice,” Mackey told reporters as he was led from an NYPD stationhouse following his arrest. “Ask for the DNA at the scene of the crime.”

During a Sunday court appearance, Mackey was ordered held without bail, according to public online records. He is due back in court Friday.

Submit tips to police by calling Crime Stoppers at 1-800-577-TIPS (8477), visiting crimestoppers.nypdonline.org, downloading the NYPD Crime Stoppers mobile app, or texting 274637 (CRIMES) then entering TIP577. Spanish-speaking callers are asked to dial 1-888-57-PISTA (74782).