B0STON -- A Massachusetts man and his cousin were arrested in New York Tuesday in connection with the shooting death of a teenage mother from Southbridge there over the weekend.

Carlos Cruz, 36, and his cousin, Devon Miller, 25, of the Bronx, was charged with the slaying of Chelsea Frazier, 18, according to WABC-TV in New York.

Frazier was shot twice on an isolated Bronx street Sunday night while her 1-year-old son Alijah sat in the back. She was later pronounced dead at Jacobi Medical Center.

The 14-month-old boy was unharmed.

Cruz, her fiance, initially told police the shooting was part of a robbery attempt. He was also shot in the leg. He said he pulled over in a secluded area of the Bronx's Castle Hill neighborhood because the baby was fussy, and a man appeared demanding his necklace.

He and Frazier both lived in Southbridge, Mass., and were engaged in a custody battle, her parents said after the shooting.

"Something is not right," Frazier's grandfather, Robert Manthorne said.

"One way or another he would have custody of the baby, because that was a way to hurt her," Frazier's grandmother Shirley Manthorne said.

The Manthornes said Frazier was a good mother.

"She loved this baby. He was gorgeous and has her dimples, big brown eyes like her. He's got her personality," Shirley Manthorne said.

The Manthornes said that when Frazier tried to break up with him, he threatened her with the baby.

"He was going to take the baby out of state. She wouldn't be able to do anything about it," Shirley Manthorne said. "Maybe one of the reasons why she (went to New York) was because if she went, she could bring the baby back with her."