I haven't read anything linking Saeed to the Mumbai attacks, nor has India offered any evidence linking Saeed to the Mumbai attacks.
The two main masterminds were LeT leaders, Lakhvi and Shah, I believe.
India's concerns revolve around Saeed's past associations with the LeT, and disbelief over any 'renouncement of violence' he may have professed.
Even the UN listing of the JuD as a terrorist org. does not mandate his arrest automatically, AFAIK.
On restraining public anger, if it was just a matter of 'public anger', India would have acted militarily after the Mumbai attacks. A government cannot function on 'anger', it has to calculate the pros and cons of every action it takes.
If you are referring to military strikes in Pakistan, that will not happen - what will happen is enormous global pressure on Pakistan to immediately shut down not just the JuD and LeT, but every single Kashmiri group, whether or not they have committed terrorism. Which is why it is in Pakistan's interest to maintain very close tabs on these groups, and why the Mumbai attacks were never in Pakistan's interest either.
Attacks like Mumbai put Pakistan at a severe disadvantage diplomatically.
Military action will result in a stalemate, at great expense to both nations, as it did in 2 out of the 3 past wars.
Has this angel of a man ever been implicated in any attacks earlier? Forget India, why would anyone believe that he has renounced violence? How about Mr.10%, he's busy running the country, where's the judiciary when you need them?
or maybe I am underestimating how devoted Pakistan really is to justice. I'm sure Pakistan has never made any exceptions, especially not for the Americans.
You underestimate how angry the people really are, in the event of another attack India will be under enormous pressure to act militarily.
Look at it this way, after Mumbai, Pakistan was under pressure, JuD was banned, people were arrested. Not two days ago all those people were released and Pakistan now risks losing whatever little credibility it had left in India.
More and more people are starting to think that dialogue is futile. Say a bunch of fanatics blow up an airport somewhere in India tomorrow, instead of dying at home, why not take the fight to the enemy? these are after all non-state actors we're talking about right? We need to go down there and make them sorry they were born.
Say India does opt for military strikes against terrorist hideouts, I know you think it will lead to a war, but that might not necessarily be the case. If Pakistan cannot control these 'non-state actors' who are responsible for murdering hundreds of innocent Indians, then India simply has no choice but to try and protect itself, I think Pakistan could crush these fools if it wanted to, it doesn't because it either cannot or will not. if it genuinely cannot then we'd be doing Pakistan a favor, if it simply will not, it faces the prospect of war on two fronts. Pakistan is already fighting the Taliban and gang, another attack on Indian soil and it will have to pick between India or JuD and 'gang'.
I've said it before and I'll say it again (since it applies), India needs to address this issue of plausible deniability. Turning a blind eye is no better than helping. If India makes good on the threat of strikes, Pakistan will have to take a more proactive approach towards shutting down these groups once and for all. What makes you think Pakistan will retaliate against India when we're busy targeting mad men who are supposedly beyond their control. As in every other field of human endeavor, America is the pioneer.
Why would Pakistan want to fight India over terrorists anyways? Not to mention that the Taliban would take the opportunity to win public support and run riot across Pakistan, under these circumstances, it is in Pakistan's interest to keep a check on any and all groups that seek to harm India. My point simply is that India should make the repercussions clear for not doing so.