The largest cash reward in Crime Stoppers' history was issued Tuesday for information leading to an arrest in the killing of a medical researcher.

Gelareh Bagherzadeh, 30,  was shot and killed in her car on Jan. 16. She was outside of her home at the Woodway Point Townhomes on Augusta Drive near Sugar Hill in the Galleria area when she was shot.

Bagherzadeh was a genetics researcher at M.D. Anderson.

Friends said she moved to Houston about five years ago and joined Sabaz Houston. She spent time protesting the oppressive Iranian government.

Houston police said they have almost no leads in this case. They said Bagherzadeh's murder may have been motivated by her activism, but it could just as well have been a botched robbery.

"It has been four months since my sister was senselessly killed behind our house," said Bagherzadeh's brother, Ali. "As a community we should be outraged at the loss of a talented and beautiful person."

The $200,000 reward is funded by Crime Stoppers and private sources. It is the largest amount to ever be offered by any Crime Stoppers in the United States.

Officials reminded the public that a call to Crime Stoppers is anonymous and confidential.

"No one will ever know that you called," Crime Stoppers Executive Director Katherine Cabaniss said. "Crime Stoppers is a nonprofit organization that is not a part of the police department."

Anyone with information about Bagherzadeh's death is asked to call Crime Stoppers at 713-222-TIPS.