jail leak

I changed the package build scripts to build in jails instead of
chroots, but I am seeing what look like leaks in the list of jails:

dosirak# jls
   JID  IP Address      Hostname                      Path
   271  10.0.225.48     jail-57648                    /c/pkgbuild/6/chroot/57648
   112  10.0.119.181    jail-30645                    /c/pkgbuild/6/chroot/30645
dosirak# pgrep -lfj 112
dosirak# jls
   JID  IP Address      Hostname                      Path
   112  10.0.119.181    jail-30645                    /c/pkgbuild/6/chroot/30645

i.e. jail 112 has nothing running inside it, but it is still hanging
around.  Is there a good reason for this, or is it in fact a leak?

Kris