Ya know, Avengers also holds the record for best second weekend at $103 million. You think TDKR could surpass that, after some time has passed and died down a bit?
I'd bet a good bit of money on the answer being no. $161M is not exactly a low opening, even if the shooting lowered it by $20-30M. Look at it this way:
Here are the top opening weekends (subtracting midnights) and their second weekend drops:
Avengers - 1st wkd $188.7M - 2nd wkd $103.1M (-45.4%)
Spider-man 3 - 1st wkd $141.1M - 2nd wkd $58.2M (-58.8%)
TDK - 1st wkd $139.9M - 2nd wkd $75.2M (-46.3%)
Hunger Games - 1st wkd $132.8M - 2nd wkd $58.6M (-55.9%)
TDKR - 1st wkd $130.2M - 2nd wkd ???
Harry Potter 8 - 1st wkd $125.7M - 2nd wkd $47.4M (-62.3%)
So minus the initial midnights, all of the 150M+ earners dropped 45-62% in their second weekend. Minus midnights, TDKR would need to drop 20.9% or less to take the second weekend record. Larger midnights for TDKR were always going to lead to a larger second weekend drop than TDK. Maybe people going this weekend instead of last weekend will mitigate that a bit, but we aren't going to magically see an unheard of drop for the movie. I think that it is much more likely that TDKR has permanently lost some of its business and momentum due to the shootings than it is that we will see some crazy second weekend total. If TDKR's second weekend matches or comes close to TDK's second weekend, that will be a big success. Especially considering midnights were almost double.