A 19-year-old pleaded not guilty to multiple charges Tuesday, including murder, manslaughter and endangering the welfare of a child in connection to the death of, who sources say, is his girlfriend's baby.

It was the first time Jerome Thomas appeared in front of a judge since his arrest in August.

Thomas' next court date is Jan. 14, 2026.

He is set to remain in custody until then.

Back in August, police responded to a 911 call on Union Avenue in Melrose. They found a 1-year-old baby girl named Imani Mitchell semi-conscious, with bruising and swelling in her head.

She died a week later.

According to the criminal complaint, Thomas said he was the sole caretaker of the child at the time, and that he did strike the child twice with a "heavy hand," causing her to cry.

However, several members of Thomas' family showed up to court in support of their loved one.

He's a great kid. He's excellent. And this is not him," said Thomas' sister.

His family members told News 12 they were concerned with Mitchell's mother from the start of her and Thomas' relationship.

They said Mitchell's mother openly physically abused her baby and didn't feed or bathe her enough.

News 12 also spoke with a woman who claims she lived in the shelter Mitchell's mother allegedly frequented.

She said she witnessed Mitchell's mother hitting her child several times.

Thomas' sister said the family tried to intervene and end Thomas' relationship with Mitchell's mother, but it was difficult.

"He tried to leave multiple times. She had him hostage and she threatened him with the police," she said.

News 12 reached out to Mitchell's mother but has not heard back yet.

News 12 is also waiting to hear back from the Bronx District Attorney's Office for more information about the case.