Monserrate has been troubled for years - lots of scandal around him. He is a good organizer and has a strong political operation, though I think his days are numbered now. Once he committed the assault, I think it became only a matter of time before he is off to jail.
Espada was a crook the first time he was elected and he is a crook this time too. He got ousted from office last time he pulled this exact stunt, though then it was just buttressing the Republican majority. He does not appear to live in the Bronx and only won because he has high name recognition and was well funded. He was also up against another crook - so either way voters lost.
They were both lousy Democrts and should have been in jail even when they were caucusing with the Democrats. Hopefully justice catches up with them both.
Monserrate's next court date is July 2. I would suspect nothing will happen in court that day -- day before a holiday weekend. Odds are he'll never see jail time. The girlfriend doesn't want to cooperate, so the DA's office will likely offer a plea deal down to a violation (probably Disorderly Conduct) and he'll walk away with a fine.
Espada is a total scumbag. I was reading up on him last night and, yes, while he supports marriage equality, he's got his hands so dirty in a variety of financial matters that it's only a matter of time before he's indicted for something. My understanding is that into late May he still hadn't filed his campaign finance reports and that he had, at one point, been accused of illegally using campaign funds towards the legal fees of two of his lackeys who appear to have taken the fall for him when he directed funding for his health clinic towards his campaign.
I don't know, but if I'm a Dem senator on shakey ground in this political climate, I don't make enemies in my own party because I'll need their support when the sh*t hits the fan.