ctrl-c wont shutdown python talker.py node when run with sudo

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Using a Raspberry Pi 2 with Ubuntu 14.04, I can't stop the talker.py example python node) with ctrl-c when run with sudo. This is terminal output when I press ctrl-c. It appears that the node will stop but just keeps on looping.

[INFO] [WallTime: 1458450996.047358] hello world 1458450996.05
[INFO] [WallTime: 1458450997.047340] hello world 1458450997.05
[INFO] [WallTime: 1458450998.047373] hello world 1458450998.05
^C[talker-2] killing on exit
[rosout-1] killing on exit
[master] killing on exit
shutting down processing monitor...
... shutting down processing monitor complete
done
ubuntu@ubuntu:~/catkin_ws$ [INFO] [WallTime: 1458450999.047300] hello world 1458450999.05
[INFO] [WallTime: 1458451000.047296] hello world 1458451000.05
[INFO] [WallTime: 1458451001.047229] hello world 1458451001.05

rosnode kill talker

    <node name="talker" pkg="rasp_pi_test" type="talker.py" output="screen" launch-prefix="sudo -E"/>

Obviously, this example does not need to be run with sudo. A more complicated example with the same problem that involves fast gpio access does need to be run with sudo. Any help is greatly appreciated.