If I recall correctly, the only way to get a sniper rifle in that mission is to carry one from a previous mission, but I'm fairly certain that it is possible to kill Pablo with the sniper rifle without having to kill the patrol outside nor the guard in the sniper tower, as long you place yourself at the right spot and kill Pablo fast enough that the patrol and the tower sentry are too far away to spot or hear you, or if you wait long enough for the patrol to be far away enough. But if you get around to replay that level and kill Pablo with the sniper rifle, here's a cherry on top pro tip for you:
Once you've stealth killed everyone in Pablo's house (I know, easier said than done) and acquired the bomb from Pablo's office, if your cover hasn't been blown yet, enter the drug lab from the small staircase with a 90 degree curve in it. There will be a guard in the staircase that will tell you are not allowed in, ignore him. Open the first door, enter the antechamber, close the first door behind you (this is the most important step), then open the second door, enter the drug lab, close the second door behind you. Place the explosives without being spotted by the guards watching the second entrance of the drug lab. Once you're done, leave the same way you came in, making sure that you carefully close the door behind you before opening the next door.
If you do it correctly, you should be able to get inside the drug lab, place the bomb and leave without blowing your disguise in the process, and you will be able to make your way to the airplane without having a rain of bullets pouring down on you, because although the guard told you that you are not allowed in the drug lab, the guard does not recognize the antechamber as being part of the lab and by closing the door behind, he won't see you enter the lab.
The first time I read about that I was flabbergasted, that mission was a pain the first time I played Codename 47, so much guards, so much death... when I read that you could kill Pablo in one hit with the sniper and that tip to sneak into the lab, I re-installed the game, copied my old savegame and gave it a try, and playing that mission without having lead raining on you at any point in the mission, that was fantastic.
Also, although Codename 47 does not have that elusive "silent assassin" rating that we try to aim for in its sequels, if you complete a mission without raising too much alarms, the game will reward you by unlocking the Desert Eagle in the following mission. IIRC, there are seven missions you can replay to unlock the Desert Eagle: The four Hong Kong missions, the last Colombian mission, the Budapest mission and the first Rotterdam mission.
Personally, I had a bit more fun with Codename 47 than I had with Silent Assassin. Codename 47 was a bit rough around the edge and they hadn't thought about "Hey, wouldn't it be cool if we designed the game so you could complete all the levels without killing anyone but the target?", but unlike its sequel, the only thing that prevented you from killing guards in Codename 47 was your chances of survival. As such I treated Codename 47 not like a stealth game but a semi stealth, semi tactical game, I was constantly asking myself "do I silently kill this guard or I find a way to sneak by him?" or "is it time to blow my cover and gun blaze my way to the finish line or do I try to sneak some more?", and I chose the option that was the most advantageous for my survival.
In Silent Assassin, they finally introduced the rating system and it was now possible to complete the missions by only killing the target, and you could unlock guns if you achieved that elusive "silent assassin" rating, but there were also some bullshit missions where acquiring that rating was much more pain than joy. Notably:
The first mission in the game, where if you get anywhere in a twenty feet radius of a guard, even if you wears a disguise, the guard will slowly chase you everywhere you go and he will bust your disguise when he gets close enough. If you aim for a "silent assassin" rating, you can't even enter a room that contains a guard because if that guard spots you, your disguise is insta-busted and it is time to restart the mission. The first time I played Silent Assassin, I nearly outright gave up on the series because of that mission. Only the promise that Blood Money was awesome kept me through. Thankfully, the guards in the rest of the game aren't that crazy paranoid...
Until those two missions in Japan, where snipers in the watch tower can see through your disguise and start taking pot shots the moment they see you (and each of those bullets could instantly kill you), and if that wasn't enough, being spotted by any of the ground troopers results in a "HALT! I must check your identity... INTRUDER!" scenario, these two missions made me long for the days of Codename 47, where there was no "silent assassin" rating to stop me from silently sniping half of the map if doing so was more advantageous to my survival. I recall that when I replayed these missions on Professional difficulty (where you cannot save) I did not even bother with the perfect rating, I just silently took down the strict minimum number of guards and moved to the next mission.
And last but not least, that one Middle East mission where you got to sneak a huge sniper rifle across a city loaded with guards and you can't take anyone down because if you do anything else you can kiss good bye your prized rating. As for using sedatives, A) 47's sneaking speed cannot keep up with a guard's walking speed and B) unlike Blood Money, sedatives do not last forever in this game.
These four missions, where the "silent assassin" rating is more of a carrot on a stick rather than something that actually enhance the game, coupled with these problems with 47's sneaking speed and the sedatives, those things killed Silent Assassin for me. And while Codename 47 is far for being a perfect game, I personally had an easier time managing the bullshit in it than I did managing the bullshit in the second game.
Post edited November 26, 2014 by blueskirt42