MURDER IN THE FIRST

Kathleen Robertson and Taye Diggs in TNT's new detective drama "Murder In the First." (Eddy Chen / Turner / June 18, 2013)

TNT's new whodunit didn't look like a ratings stiff in its premiere Monday night.

The crime drama "Murder in the First" scored the biggest audience for a TNT series premiere in two years, which bodes well for a network that has recently struggled with new shows.

Created by Steven Bochco, of "NYPD Blue" fame, and Eric Lodal, "Murder in the First" averaged 3.8 million viewers for its 10 p.m. premiere, according to Nielsen, making it the most-watched new basic cable show launch this year. Counting its encore, the premiere was watched by 4.9 million total.

The series opener followed a particularly strong result from the Season 3 debut of "Major Crimes," which averaged 5.2 million viewers, 1.6 million of whom were in the key 18-49 demographic, up slightly from its Season 2 premiere in both measures.

The strong numbers are a welcome result for the cable channel's parent company, Time Warner, whose chief executive, Jeff Bewkes, has voiced concerns about the original programming on the company's networks, including TNT.

Last week, Turner's new chief, John Martin, sent a blunt memo to employees laying out the challenges facing the unit, writing that it has not "kept pace with the competition or, just as important, with our own high expectations."

The TNT body count includes the noir drama "Mob City," from "Walking Dead" creator Frank Darabont, which was canceled in February after posting weak numbers. Last year's summer effort "King & Maxwell" was dropped after one season.

TNT is betting heavily on its scripted series this summer, with nine originals on the slate, including Season 5 of "Rizzoli & Isles" and Season 3 of "Perception."

"Murder in the First" follows two San Francisco detectives investigating killings and stars Taye Diggs and Kathleen Robertson.