A federal model for state and local police seems to me to be a very bad idea.
On the surface, it may seem worthwhile to have a uniform set of rules and training.
However, this ignores the fact that each state has its own laws and police procedures.
Unlike the UK, the USA is a collection of independent states; laws are largely similar but vary by state, county, and city.
A long time ago, President Clinton attempted to put an end to the authority of the US states by signing a simple Executive Order, entitled 'Federalism'. It was the scariest thing I had ever seen. It was ignored by the press; but the conservatives made a huge issue of it and President Clinton just as quietly 'suspended' it.
http://en.wikisource.org/wiki/Executive_Order_13083
http://en.wikisource.org/wiki/Executive_Order_13095
This is a traditional conservative issue; the restriction of the ever-growing authority of the federal government and usurpation of the authority delegated to the states.
Training of police officers to enforce STATE laws is a role that belongs to the STATE.
Attempt to 'standardize' that are, and should be seen as, attempts to override the authority of the states and strip the states of their power.
This is particularly onerous; in some ways, it can be seen as one sovereign government taking control over the training of the army of another government. Imagine if Iran had the authority to train all of Iraq's armed forces. Do you imagine that Iran might be able to establish some level of control over Iraq in this way? I do. While that may seem an extreme example, it has some applicability. The states have no standing armies; even the 'national guard' of each state is under the control of the federal government anytime they wish to exercise it (which they do and have in recent times). The state, county, and local police forces are the only analog to an 'army' that the states have.
In fact, in Michigan, the state police are one component of the state self-defense forces; Michigan even has a voluntary, uniformed, para-military 'guard force' which is not the national guard or the reserves, strictly under the control of the state and not the federal government. This is not uncommon; many states consider the state police to be the equivalent of a standing army for the states themselves. To give control over their training to the federal government would be like Iraq turning over their armed forces to Iran for training.