Sylvia was his first marriage partner.
He, according to some published reports and some comments from purported former co-workers and girlfriends tended to play the field with younger women.
But he did get near the altar a couple of times.
He told one girlfriend that he had left a girl at the altar, and broken off an engagement with another (and seemed to be pleased with himself for doing so).
A co-worker seems to have a similar story - and posted that Pardo left one woman standing at the altar, ( coworker was invited to the wedding) to her shock an humiliation, never having let on to anyone, including her, that he wasn’t in love and wanting to get married.
He cleaned out their joint account they had a blew town for a month, (leaving her with bills and all the wedding expenses.)
He returned a month later to his place of work (JPL) and acted like nothing strange had happened, and could not understand that he no longer had a job there.
Another girlfriend from his much earlier college days says that Bruce was a fun boyfriend at first, but handled resentment at her refusing to sleep with him with passive-aggressive payback...setting up or agreeing to dates cheerfully, and then failing to show up. Never said when he was upset or mad...he just exacted his revenge. So she found him too frustrating a partner and quit dating him.
Those women, the previous girlfriends and fiancees (and their families), are fortunate to have escaped the cold-blooded killer.
I wonder how he finally got to the altar. Beware of persons who easily become resentful or nurture vendettas. I had a neighbor like that a few years ago, very vindictive re the slightest thing. I thank God he didn’t act out worse than he did. These types are powder kegs waiting to blow.
The TV news has stopped mentioning him, so maybe you found this about his past online?