I think for candid mug shots in the US, you need to look at the photos taken by police before and after the "official" mugshot. Those unofficial pictures often capture the racketeers/gangsters playing up to their audience, or at least exhibiting the bragadocio normally on display when the racketeers interacted with the police.
Here's a good example - in this photo from 1931, Mad Dog Coll and his crew have been hauled into police headquarters in Manhattan to be charged for the infamous "Harlem Baby Murders."
Basically, during the on-going war for control over Bronx/Harlem beer distribution with his former employer Dutch Schultz, Coll had started bumping off Schultz employees in broad daylight. Schultz had a good working relationship with the "uptown" Italians (not to be confused with the downtown boys who eventually put him on the spot in that chophouse in Newark) like "Tough" Joey Rao. Rao ran a social club on 107th street between 2nd and 3rd (which also happens to be the street I grew up on) and was the target in question on a hot summer day in 1931. Coll and his henchmen, presumably looking to take out Rao, opened up in the middle of a busy street - whoever the real target was managed to elude the gunmen, but several Italian children playing on the street were not so lucky.
As a result, Coll became known as the baby killer and was hauled in as the prime suspect. As you can see from the photo, he didnt appear to be too distraught over the killing or cowed by the police. Coll is the guy to the far right with the matinee idol looks (hair dyed black and moustache grown in to evade the police manhunt) with the peaked lapels:

Coll was eventually acquitted in the case. But all of the men in this photo were dead within months. Toughy Odierno and Frank Giordano went to the chair at Sing Sing for killing a Schultz beer drop attendant in broad daylight. A Con Ed worker saw the whole thing while peering out from a manhole cover. Patsy Del Greco was shot dead in a Bronx apartment, and of course, Coll was famously shot 18times while allegedly being kept on the line by Owney Madden in a phone booth in the pharmacy across the street from his hotel on 23rd street. Mike Basile may or may not have been the bodyguard who took a walk when Madden's gunman walked into the pharmacy with a tommy gun to take the "mad dog" out. I'm not sure what ultimately happened to him.