Military choppers over New York?

For the past 1/2 hour or so (10 PM local), I've had two (presumably)
military choppers in the air over my house, about 5 miles NE of
LaGuardia. At one point, one was hovering right over my house, and the
other searching the ground with a spotlight nearby. Based on traffic
calls, the two of them are between 500 and 800 feet. They're basicly
parked right in the final approach course to the active runway.

I'm assuming they're military because 1) nobody else flies formation
choppers, 2) The one right over my house looked way too big to be
anything else, and 3) I'm monitoring LaGuardia tower; it's obvious he's
talking to both of them, but I'm hearing none of that traffic. I assume
he's got them on the military freq (263.0, which my scanner doesn't get).

Anybody have any idea what's going on?