Use REST API to search tickets by client username

We'd like to display a list of tickets in our portal to logged in users. It seems the easiest way to do this would be the using the REST api and finding tickets by client username.

I've tried clientReporter.username, but that just gives me this error:

sqlStringForKeyValueQualifier: attempt to generate SQL for com.webobjects.eocontrol.EOKeyValueQualifier (clientReporter.username = 'singerkd-admin') failed because attribute identified by key 'clientReporter.username' was not reachable from from entity 'JobTicket'.

Any ideas?

Thanks!