ABC’s “Blind Justice” debuted last month to a decent audience, with viewers curious how ABC could pull off the ridiculous-sounding concept of a blind cop with a gun roaming around the streets.
   That curiosity was apparently sated quite quickly. Since its debut, “Blind” has lost nearly one-third of its audience, and it was down once again last night.
   Last night’s episode averaged a 3.0 average, according to Nielsen overnights. That’s 33.3 percent lower than its premiere average of 4.5 on March 8 and, maybe more importantly, down 19 percent from the 3.7 “NYPD Blue” averaged this season in the same 10 p.m. timeslot.
   Whereas four weeks ago it looked as if “Blind” had a chance to make the fall schedule, it’s now just a placefiller until ABC finds something better next year.
   “Blind” fell to a series low 2.6 two weeks ago and a 3.0 last week. The show has averaged a 3.2 rating since its debut, but that continues to fall each week.
   Even head-to-head against a rerun of NBC’s “Law & Order: SVU,” “Blind” struggled. The show finished third in its timeslot behind “SVU” and CBS’s “Judging Amy.”
   Bad reviews for “Blind” didn’t seem to hurt its initial tune-in, but audiences evidently agreed with the reviewers. The show will finish out the season in the time slot.
   Thus Tuesday looks like an increasingly troubled night for ABC with “Blind’s” falloff.
   The network has also seen decreases for its block of sitcoms from 8 to 10 p.m., with at least one or two likely to be canceled or rescheduled.
   Fox’s “American Idol” was the night’s highest-rated show in 18-49s, averaging a 10.5 during the 8 p.m. timeslot. That helped the network to a fairly easy first-place finish for the night, with an 8.6 average rating and a 23 share. CBS finished second at 3.7/10, NBC third at 2.7/7, ABC fourth at 2.6/7, the WB fifth at 1.1/3 and UPN sixth at 0.8/2.
   Fox finished ahead of the combined broadcast competition at 8 p.m. with “Idol’s” 10.5 average rating. CBS was second during the hour with a 2.9 average for “NCIS” and ABC third with a 1.8 average for the comedies “My Wife & Kids” (1.8) and “George Lopez” (1.9).
   Fox led again at 9 p.m., this time with a 6.7 average rating for its surging medical drama “House.” CBS was second with a 4.9 average for “The Amazing Race” and ABC third with a 3.1 average for “According to Jim” (3.1) and “Rodney” (3.0).
   NBC jumped into the lead at 10 p.m. with its rerun of “SVU” averaging a 4.2 rating. CBS was second with a 3.4 average for “Judging Amy” and ABC third with its 3.0 average for “Blind Justice.”
   Fox finished first for the night among households with a 12.7 average rating and 20 share. CBS finished second at 8.3/13, ABC third at 4.9/8, NBC fourth at 4.7/7, the WB fifth at 2.0/3 and UPN sixth at 1.5/2.