Prosecutors on Friday charged the former boyfriend of Ugandan Zewu Nantambi in her murder Sun., Dec. 23 in North St. Paul, Minnesota, United States, the St. Paul Pioneer Press reported. Jonathan Samuel, 45, of Nigeria, was the former boyfriend of Nantambi, 28.

Witnesses told investigators Samuel would not leave Nantambi alone. One witness said that after the couple broke up, Samuel would show up at Nantambi’s workplace and apartment and call her on the telephone.

Nantambi was born in Jinja and moved to the St. Paul area three and a half years ago.

Sunny Lwetutte, 32, also of Uganda, was initially held by police, but he was released Friday, the paper reported. Lwetutte was a long-time friend of the victim and was living with her and her brother. According to court records, he was watching television on the 23rd when he heard gunshots from the room where Samuel and Nantambi were arguing. Lwetutte told investigators he struggled with Samuel for control of the gun after Samule threatened him, and managed to wrest control before the police arrived.

Samuel has disputed the account, claiming that the gun was Lwetutte’s and that Nantambi was shot twice accidentally while the two men struggled for control of the gun, according to the paper. However, investigators found a bullet hole and bullet fragment in Samuel’s vehicle consistent with the .22-caliber handgun used to kill Nantambi.

Samuel came to the U.S. from Nigeria in September 1997, and his visa expired that December, more than four years ago.