Root cert import & trust in Leopard

Does anyone know if there is a way to specify the trust of a certificate in Leopard through the command line? Perviously under Tiger you could use certtool to import the root cert into the X509Anchors, Under Leopard Apple says they should go into the System.keychain. If I import the cert into the SystemRootCertificates.keychain or the System.keychain with certtool, it remains untrusted. I need to be able to change the trust in addition to importing it. Thanks!