In all likelihood, Spender had a difficult childhood. He never knew his father, and his mother
was a little flaky.
She brainwashed young Jeffrey into thinking he'd been abducted by aliens.
(Either that, or he actually was abducted by aliens, which is probably worse.) We don't know what Cassandra told her son about his father, but it can't have been good,
because as an adult, Spender refuses to even open letters from Dad.
As a new and ambitious Special Agent for the FBI, Spender had friends in high places
and seemed to destined for great things. But due to family problems, he had to leave the Bureau rather abruptly, without
giving two weeks' notice, turning in his parking pass, or scheduling an exit interview.
He probably can't count on A.D. Skinner for a letter of recommendation for his next job...whatever that is.