Despite felony charges, 49ers pick up Aldon Smith's option
On Friday, the 49ers showed they want to keep control of Smith's contract, exercising his 2015 option worth $9.75 million. Until next March, the option is only guaranteed if Smith suffers a major injury in 2014 that would affect the 2015 season. The 49ers also could pull the option before the end of the 2014-15 league year in March, or they could trade Smith.
SNIP
Had the 49ers not exercised the option, Smith, 24, would have been set to become a free agent after the 2014 season. If the 49ers had decided not to pick up the option and then placed the franchise tag on Smith instead next winter, his 2015 salary would have increased to the $12-13 million range.
Because of that, it was widely considered the smart football move for the 49ers to exercise the option.
http://espn.go.com/nfl/story/_/id/10873834/aldon-smith-2015-contract-option-picked-san-francisco-49ers
They must have an out should he end up in jail for the several felony assualt weapon charges facing him. Besides the favorable contract situation, you could understand why they're keeping him ...
Since entering the league in 2011, Aldon Smith has recorded one sack every 46.9 plays - the best rate for anyone over that span with a minimum of 10 sacks.
Player / Plays Per Sack
Aldon Smith / 46.9
Antwan Barnes / 47.4
Robert Mathis / 57.4
Mark Anderson / 59.5
DeMarcus Ware / 61.4