A powerful Reuters special report, their title is 'The real force behind Egypt's 'revolution of the state':http://www.reuters.com/article/2013/...99908D20131010

It starts with (minus one passage):
Little attention was paid when a group of Muslim Brotherhood leaders broke free from their cells in a prison in the far off Wadi el-Natroun desert. But the incident, which triggered a series of prison breaks by members of the Islamist group around the country, caused panic among police officers fast losing their grip on Egypt.

In all, 200 policemen and security officers were killed that day, Jan 28, called the Friday of Rage by anti-Mubarak demonstrators. Some had their throats slit. One of the Muslim Brotherhood leaders to escape was Mohamed Mursi, who would become president the following year.
As Egypt appeared to move towards the removal of President Mursi's MB government, much was made of the potential for interaction with the Egyptian military by the US military - was there a relationship with the "batons".