Eh...what I meant was that if it were based on the movie tie-in, the name 'Sullivan' is fine by me. Sorry for the confusing statement. Other than that, this is pretty much okay.

In the movie tie-in, The O is dropped from his name
by an immigration officer at Ellis Island. I appreciated the quark, because in the real world, I have an Irish name that's gone through the same altering on some records.

Last I checked the original text, his name was O'Sullivan. He wasn't a cop, rather a full-time soldier for John Looney.

If this is based on the movie book, though, then it's okay...but a couple of problems even so.

1. Sullivan/O'Sullivan works in Rock Island.
2. He is a little darker than that.
3. He never really liked being a gangster.

But...well, it's your story.