Pakistani scientist Aafia Siddiqui was sentenced to 86 years in prison by a US judge in 2010 for attempting to kill US soldiers in Afghanistan. Her nickname refers to the terrorist organization Al Qaeda.
The rabbi and several other people are being held hostage in Colleyville near Dallas. The authorities are negotiating with the man.
The hostage-taking in the synagogue is said to have started during a service that was broadcast live on the internet, but was cut short.