Via AP:

 Gunmen on motorcycles assassinated an Iranian nuclear physicist on Saturday, Iranian media reports said, in a killing that bore similarities to other slayings of scientists involved in the country’s nuclear work in recent years.

The semi-official ISNA news agency identified the victim as Darioush Rezaei, a 35-year-old physics professor involved in Iran’s nuclear program, and said he was shot dead in front of his home in Tehran. Iran’s official IRNA news agency also reported the killing but had few details on the attack or the man’s background….

Rezaei’s expertise — neutron transport — lies at the heart of nuclear chain reactions in reactors and bombs.