YOUNGSTOWN, Ohio (WKBN) — The lead investigator in the late 2018 murder of a man and wounding of his girlfriend explained Thursday to jurors in Mahoning County Common Pleas Court how he built his case against the suspect.

Youngstown Police Detective Sgt. Chad Zubal told jurors how he was able to determine Lavontae Knight, 27, of Ferndale Avenue, should be charged with aggravated murder for the Dec. 30, 2018, shooting death of Trevice Harris, 37, and attempted aggravated murder for wounding his girlfriend as well as charges of kidnapping and aggravated robbery.

The case began Monday with jury selection before Judge John Durkin, and jurors began hearing testimony Tuesday.

Zubal said one of the keys to the case was Harris’ girlfriend, who was with him in an SUV at Erie Street and East Earle Avenue where prosecutors said Knight fired several shots, hitting Harris in the head and the girlfriend in the back and shoulder.

The girlfriend testified this week she went to meet Harris at a home on Ferndale Avenue, where Harris was with a man she knew as “Slim” who prosecutors said is Knight.

Knight and another man forced Harris and his girlfriend into her Mercedes SUV, with the other man driving. At East Earle Avenue and Erie Street, they got out of the SUV, which is when the pair were shot.

The girlfriend drove to a Market Street gas station to call police. Harris died in an ambulance on the way to a hospital.

Zubal said he was able to interview the girlfriend in the emergency room while she was being treated for her wounds and she told him it was “Slim” who shot her and Harris. The next day, she was able to pick Knight out of a photo lineup.

Zubal said he also used phone records to establish a connection between Knight and Harris and that he knew Knight went by the street name “Slim.”

Defense attorneys said in opening statements that the girlfriend had given Zubal pictures of a man who she thought accompanied Knight but those leads did not pan out. Zubal said that was true but he also said she never wavered from the fact the man she knew as “Slim” was the man who shot her and Harris and her statements to police were consistent.