Gelareh Bagherzadeh, 30, was driving through her Houston townhouse complex around midnight on Monday when she was shot dead through her car window.
"When officers arrived, they found a vehicle had run into a garage door at that location with the engine running and tires spinning on the pavement. Ms. Bagherzadeh was found slumped over in the driver's seat," the Houston Police Department said in a statement.
Authorities said nothing appeared to have been stolen from her car. Her cell phone and purse were found inside.
"Homicide investigators responded to the scene and were told by witnesses that several gunshots were heard, a crash and then tires squealing," the statement said.
Police told ABC News' Houston affiliate KTRK that the last person to speak to Bagherzadeh was her close friend and ex-boyfriend who was on the phone with her when she was shot.
"[The boyfriend] heard a loud thud. He doesn't recall hearing any gunshots, but a loud thud and then a screeching noise," Richard Bolton of the Houston Police Department Homicide unit told KTRK.
Bagherzadeh was of Iranian descent and was outspoken in promoting Iranian women's rights and criticizing the Iranian government, according to interviews she had done with the Houston Chronicle.
Photos and video from the newspaper's website show Bagherzadeh participating in a 2010 protest calling for a regime change in Iran. At the time, she requested that her name not be used in the video because she was afraid of persecution, according to the Houston Chronicle.
"It's not believed that she was targeted because of her ethnicity or because she was an activist," Houston Police Department spokesman Victor Senties told ABCNews.com.
Police don't currently believe her death was related to her activism, but the death is mysterious. Bagherzadeh's cell phone and purse were still inside.
"They're still in the process of investigating," Senties said. "We're still trying to question anyone that might know her or might know if there was someone that wanted to harm her."
Bagherzadeh was studying molecular genetic technology at the Texas Medical Center.
At about 11:45 p.m. on Monday night, Houston police responded to a discharge of firearms call at 800 August Drive. When officers arrived, they found no evidence of any shooting and left. Forty-five minutes later, they responded to a call for a shooting from 894 August Drive. Paramedics responded to the scene and pronounced her dead, according to police.
Another unexplained element is the question of why Bagherzadeh had turned her car onto a dead-end drive, in the opposite direction from her home.
"We don't know why she ended up back there on the back end. Maybe they only lived here for a short time, maybe she's unfamiliar with the property, because from what we understand from friends and relatives is she always parks on the street in front of her townhome," Bolton said.
Investigators are looking into neighborhood surveillance footage to see "if there's anything that could possibly help," Senties said.
A neighbor who did not wish to be named told ABCNews.com that the shooting was "very unusual." He has surveillance cameras outside his home and said police came to his house to collect his tapes.
"I've been living her since 1976 and never heard of anything like this before," he said. "It's a terrible, terrible thing."
Bagherzadeh's family could not be reached for comment.
