PITTSBURGH (KDKA) — A California man has been charged in two rapes in Pittsburgh.

Pittsburgh sex assault detective say the first rape happened in the South Side Flats inside a home on Wharton Street.

A 23-year-old woman told police 29-year-old Akaninyene Akan walked inside her home shortly after 1 a.m. on Sept. 4, 2010.

Akan allegedly acted like he was confused about where he was, told her he would kill her if she made a sound and then raped her.

Investigators say the second rape happened on Sept. 12, 2010 in the 3300-block of Parkview Avenue in Oakland.

The victim described her attacker as an African-American man, 5’7” to 5’8” with a muscular build. She said he spoke with an accent.

Akan is a native of Nigeria.

The victim told police Akan climbed through a bedroom window, raped her, told her he would kill her and went on to say that he killed an ex-girlfriend and her mother and said he spent seven years in jail for those murders.

Police say what ties Akan to both rapes is DNA from a cigarette he tossed during a routine interview.

Akan is a mechanical engineer who worked in Pittsburgh at the time of the assaults and then relocated to Orange County, California where he was arrested, jailed and then extradited to Allegheny County.