Authorities say it was a murder suicide.
The baby's mother tells ABC11 her daughter's father had threatened her when they broke up, but she didn't know he would do something like this.
"He told me that he was going to do something, but I didn't think that he would kill his daughter over me because we broke up," Tyaijah's mother, Latoya Smith said.
Smith says her boyfriend of four and a half years, Tyrone Hester, snapped on Saturday. The two had just broken up last week. He had their daughter, 22-month-old Tyaijah, with him at an apartment complex.
"I was talking to him on the phone. We were arguing, and he was like, 'Since you want to do something to hurt me, I'm going to do something to hurt you.' So I hung up," Smith said. " He called back and said 'Baby, can we please go back together?'"
A few minutes later, eyewitnesses say Hester took Tyaijah in his arms, went behind the building, and shot her. He then shot and killed himself.
The 22-month-old died at the hospital, after being rushed there from the scene.
"I feel hurt. I lost my daughter," Smith said. "She was a good playful baby. I love her. I miss her, and she's going to be in my heart."
Smith says she ended things with Hester because it was an abusive relationship.
"He probably was just mad about it, drunk, he couldn't take it. He loved me," Smith said. "But I just couldn't take it because he always used to beat on me."
Smith says this Mother's Day is bittersweet.
"I'm going to make this a good day for me. I mean, it's hurtful. I don't really want it to be a good day, but I still got two more kids, so I'm still a mother," she said.
Hester had recently been charged with misdemeanor assault on a female.
Smith and her family are now trying to make funeral arrangements, as painful as it is.
"I don't want to bury my child. I wanted my kids to bury me," she said.
Hester's mother was not up to speaking to ABC11, but an aunt says he was a good dad.