There's audio of the chase in the video below. It all started with a near miss.
Some highlights:
[00:00:15.52 --> 00:00:26.80] We just had a near mid-air with a quadcopter. I'd like to do a 360 just to see if it's still flying.
[00:01:27.36 --> 00:01:40.00] Yeah, I got a visual on the quadcopter, it's about a hundred feet above us (...).
[00:05:11.92 --> 00:05:20.96] Traffic off your left-hand side is eight-star helicopter, they're tracking a drone (...)
[00:05:22.48 --> 00:05:29.28] It's a quadcopter and they're able to see it with with their night vision.
[00:06:08.56 --> 00:06:10.68] OK, you said the drone's at 4000 feet?
[00:06:11.44 --> 00:06:24.00] That's what it looks like, I'm at a 3800 and it's just a really dim flashing green light. I can't track it on goggles, so I'm just physically tracking it right now.
[00:07:26.16 --> 00:07:32.00] He's gonna be directly above us. I'm just looking up through the top window here (...)
[00:08:28.88 --> 00:08:33.40] OK, we're climbing 3.8 now.
[00:08:45.60 --> 00:08:52.88] Yeah, he got within about 50 yards of us on departure (...)
[00:08:52.96 --> 00:08:59.72] OK, my partner still got eye on it. We're just gonna try to climb up, so we're just above it.
[00:09:44.72 --> 00:09:48.32] All right, I lost visual with it in the turn, try to reacquire here (...)
[00:09:50.80 --> 00:10:02.12] Still got it, it's still off to our west. We're at 4.4 and he's saying it's like still 500 above us, so I think it's still climbing, probably above 5000 now.
[00:11:23.92 --> 00:11:37.04] Tower air 2, it is directly above us now, and it's probably still 2000 feet above us now, so he's gonna be up over 7000 feet
[00:14:16.24 --> 00:14:43.76] All right, roger that. We're finally up to his altitude, so he's 7600 up here now. He's about a quarter mile off to our west we're trying to get an idea of the size of this thing because it's moving pretty fast (...) it's between us and a mountain.
[00:14:46.00 --> 00:14:55.28] If you like, we can extend east. We can climb up to 9500 and try to get him on the camera and then we can try to track him to point origin.
[00:14:55.28 --> 00:14:59.80] Yeah, he's kind of orbiting around us now.
[00:15:30.24 --> 00:15:55.16] Yeah, he's directly north of us, quarter mile now, maybe 100 feet above us.
[00:16:23.04 --> 00:16:29.76] Negative, my observer caught him through the window, front window.
[00:21:50.56 --> 00:21:55.00] All right, searching on camera.
[00:22:39.28 --> 00:22:50.36] Yeah, he is northwest of us now, coming around in the orbit. He's southwest bound now, and probably 10,000.
[00:24:06.24 --> 00:24:10.80] We're not getting anything on the camera.
[00:24:32.80 --> 00:25:42.44] I'm unable to get a visual and I'm looking down over the city. We're still searching with the camera around here he's probably up above ten five now.
[00:26:24.08 --> 00:26:41.48] He's going straight up now. He's going right over the top of us, so he's changed his orbit drastically. We lost sight of him now, he's directly over the top of us, going back towards dm and probably above 11000.
[00:30:17.44 --> 00:30:57.40] Shot straight up again. He's probably about 12 or 13 000 now. He is east of us by about three quarters of a mile and 2000 above us. Still generally doing counterclockwise orbits.
[00:32:28.56 --> 00:32:38.40] And, that's crazy man to be that far. They don't think it's radio controlled.
[00:32:44.08 --> 00:32:48.16] The night vision's helping him out, yeah.
[00:33:03.76 --> 00:33:09.96] He's not coming up in that camera (...)
[00:34:14.40 --> 00:34:32.44] He's playing around with us now. He's not letting us get a good orbit follow on him. He keeps cutting that orbit in half and then we lose him, and then we try to reacquire. So, every time we come around to 350 degrees, or something like that, he'll cut across the top of our rotor, and then we lose him and so.
[00:37:21.36 --> 00:37:28.48] Now we're trailing about three miles to your six o'clock and we're just standing around here trying to pick him up.
[00:39:52.96 --> 00:40:00.88] We haven't pinned, that's probably about 65 knots right now, that he's moving westbound.
[00:45:07.68 --> 00:45:10.88] All right, that's our visual sighting with him, it's been about 40 minutes. So, you've got to be getting super little in the battery.
[00:45:14.32 --> 00:45:19.28] This would be like no battery I've ever seen. Not with the activity and altitude he's been playing with, but we'll see.
[00:46:29.84 --> 00:46:36.20] Yeah, we're still tracking you with the camera. We're not getting any thermal feedback at all.
[00:50:43.28 --> 00:51:00.12] Unfortunately, we're probably...we might have 15 or 20 minutes left.
[00:52:25.60 --> 00:52:32.12] and my partner just lost him in that cloud somewhere.
[00:52:37.20 --> 00:52:43.44] Yeah, the clouds look to be a little bit lower out here.
[00:52:41.04 -->00:52:50.04] So, if you're a celestial geek, my partner is saying the middle star of Orion's belt is where he last had him
[00:56:33.44 --> 00:56:36.72] Sorry, we couldn't hang longer.
[00:56:37.44 --> 00:56:42.00] No worries, like, he's got atomic battery.
[00:56:40.56 --> 00:56:50.00] Yeah, I was really wanting to see what kind of guidance system that has. That's not being driven by some iPhone somewhere.
[00:57:03.28 --> 00:57:11.76] Now, we'll give it a search here for a few more minutes. See if we can visibly acquire them. We're not seeing them yet.
[01:01:53.04 -->01:02:01.28] Yeah, from our measurements here it looks like you guys tracked it for 40 miles and about 10,000 feet in altitude.
[01:02:01.28 --> 01:02:07.84] Yeah, something special. I was really hoping we could see what that thing was built out of.
[01:02:20.88 --> 01:02:35.64] Yeah, we've taken about eight of those into custody, over the years, and none of them have come close to what that thing's doing. Got a good guidance, come on.
[01:02:43.84 --> 01:02:54.04] And I also come from the military UAV world, and I don't know of any small UAVs with that kind of endurance.
Source: https://youtu.be/YawBzT1sE6E