This happens on version 1.561 as well as the LTS 1.532.3 version.

Jenkins crashes if you kill a free-style job that uses su to run as another user. Nothing is logged, and there no heap dumps are created.

To repro:
-----------
1. Launch Jenkins as root
2. Create a simple sleep script on the local file system, eg /tmp/sleep.sh...
#!/bin/bash
sleep 6000
3. Create a free-style software project build, that runs this shell command
su <some user> -c "cd /tmp/ ; ./sleep.sh"
4. Run the build
5. Wait a few seconds
6. Kill the running build
7. Refresh your browser.