At the police station

Answer from: Andrew
You go in through the back where the windows are, theres it a place that i believe you have to smash through a window (if i remember rightly)

Answer from: tank engine
I am having the same problem. There is not a smash button appearing on the cracked window in front of the hostage that is in the main room. I cant get in the main room.

Answer from: Bug
There is not a smash button but i rescued all hostages

Answer from: Annoyedplayer
Im having also this problem its really frustrating because there is no other way in

Answer from: JLT
I am also having this problem. I've rescued the hostages (although they don't move, and still show up as blue diamonds on my map), and I can't get into that building through the back window. I know it's supposed to crack open, but there's no smash button...

Answer from: JLT
GOT IT: It stopped glitching. Here's what you have to do.
1.) Reboot your phone.
2.) Play another chapter (it gets the game to refresh a new level)
3.) Go back to the Police level.
4.) The glass won't have a 'smash' button until after all the hostages are freed. For some reason, when I was having problems before, I would save the hostage, but they wouldn't move and I wouldn't get any credit. If you do it right, the three hostages will run out of the room and you'll get a note saying '1 out of 3 saved.'
5.) After you get credit for saving all the hostages, the glass can be smashed.

Answer from: LB
Hey. Just came here looking for an answer. Thanks you so much to JLT for posting the solution. It was driving me mad. Cheers.

Answer from: MR
Thanks mate - this was annoying me too

Answer from: Sp1tfire
Thanks, JLT. This was the only solution that worked. Looks like this level is a lil bit bugged. Hostages didn't move when i was saving them. I almost went nuts trying to break that glass.

Answer from: afifrauf1234567
When u start mission police station then first u hve to rescue 2 hostages thn u will hve to deactivte all cameras from control tower then go in frnt of crack glass u will get an option to break then beat all enemies then 3rd hostage will also rescued from there then skip conversation and then ho near police van on bridge u will see red mark then stand There u will leave this level and then your new mission will start