Deputy U.S. Marshals and Mercer County sheriff's deputies on Wednesday raided the Fort Wayne home where Martin was staying, the news release said, though police did not disclose the address of the home.
Police also found an AK-47 assault rifle inside the home, according to the release. The U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives is investigating the ownership of the rifle.
Martin was taken into custody without incident. A warrant for Martin's arrest was first issued Nov. 8, the same day as Shinn's killing. U.S. Marshals joined the manhunt the next day.
Rockford is about 40 miles southeast of Fort Wayne.