You beat me to it. Turner is among the worst jump shooters in the league. For comparison
Turner 38% EFG
Jeff Green 44%
Ray Allen 55%
After a bit of searching, I did find a worse shooter.
Tony Allen 34%
Is this career figures? Can we do a comparison of his stats while he was in Philly?
Here are some career numbers for shots at different ranges. Sorry bout the formatting. basketball-reference.com
FG%
Season Tm 0-3 3-10 10-16 16 3 3P
2010-11 PHI .663 .356 .366 .387 .318
2011-12 PHI .675 .402 .419 .389 .224
2012-13 PHI .546 .346 .428 .390 .365
2013-14 TOT .584 .371 .391 .396 .321
2013-14 PHI .573 .383 .409 .416 .288
2013-14 IND .636 .333 .333 .238 .500
Career .601 .367 .406 .391 .326
4 seasons PHI .599 .370 .411 .395 .315
1 season IND .636 .333 .333 .238 .500