The Philadelphia Inquirer reported Giocondo Navek, 39, a former resident physician at Virtua, a non-profit healthcare system in southern New Jersey, fatally shot former colleague Payman Houshmandpour outside his home April 11.
Navek killed himself as officers tried to take him into custody, The (Cherry Hill, N.J.) Courier-Post reported.
Five hours after the murder-suicide, authorities found the body of Shawna D. Givens, 35, in her Fayetteville, N.C., apartment.
Ballistics tests showed the same gun had been used in the murder-suicide and in the fatal shooting of Givens, said Debbie Tanna, a spokeswoman with the Cumberland (N.C.) Sheriff's Office.
Investigators, The Courier-Post reported, said Navek had blamed Houshmandpour for the loss of his job at Virtua but did not provide details.
After Givens' body was found, authorities suspected Navek had killed her but Tanna didn't directly link him to her death.
Givens had been dating Navek for four or five months, the Inquirer said. They had met at the Womack Army Medical Center at Fort Bragg, N.C., where Navek, who was a captain in the Army Reserve, had been a physician since September.
The Inquirer said Givens and Navek had visited his family in Philadelphia during the Easter holiday and they left for North Carolina April 8.
Tanna wouldn't identify the type of handgun. Officials in the Camden County Prosecutor's Office said they recovered a Sig Sauer .357 handgun from Navek's vehicle and at least 11 rounds of ammunition.