Here are today's top stories from The Associated Press.
Black smoke from Sistine Chapel chimney: No pope on first vote of conclave
VATICAN CITY — Black smoke poured from the Sistine Chapel chimney Tuesday, signaling that cardinals failed on their first vote of the papal conclave to choose a new leader for the world's 1.2 billion Catholics and their troubled church.
Surrounded by Michelangelo's imposing frescos imagining the beginning and the end of the world, cardinals locked themselves into the chapel following a final appeal for unity to heal the divisions that have been exposed by Pope Benedict XVI's shocking resignation and revelations of corruption and mismanagement in the Vatican bureaucracy.
Led by prelates holding a crucifix and candles, the 115 scarlet-robed cardinals chanted the Litany of Saints, the hypnotic Gregorian chant imploring the intercession of the saints to guide their voting, before the master of liturgical ceremonies intoned "Extra omnes" or "all out" and closed the heavy wooden doors.
Outside, thousands of people braved cold night rain and packed St. Peter's Square, eyes fixed on the narrow chimney poking out of the Sistine Chapel roof. They were rewarded some three hours after the conclave began when thick black smoke billowed out of the chimney, signaling that no pope had been elected.
The cardinals now return to the Vatican hotel for the night and resume voting Wednesday morning.
Judge enters not guilty plea on behalf of Holmes in deadly Colorado theater shooting
CENTENNIAL, Colo. — The judge in the deadly Colorado movie theater shooting case entered a not guilty plea on behalf of James Holmes on Tuesday after the former graduate student's defense team said he was not ready to enter one.
If Holmes is convicted, he could be executed or spend the rest of his life in prison. Judge William Sylvester said Holmes, 25, can change his plea to not guilty by reason of insanity later, if he chooses.
Such a change could be the only way Holmes could avoid life in prison or execution.
Prosecutors, for their part, have not said yet whether they will pursue the death penalty, announcing Tuesday that they will make their decision known on April 1.
The judge set Aug. 5 for the start of the trial. Prosecutors and defense attorneys declined comment.
New House GOP budget again takes aim at Obamacare, Medicaid
WASHINGTON — House Republicans unveiled their latest budget outline on Tuesday, sticking to their plans to try to repeal so-called Obamacare, cut domestic programs ranging from Medicaid to college grants and require future Medicare patients to bear more of the program's cost.
The GOP plan came as President Barack Obama traveled to Capitol Hill to meet with Senate Democrats on the budget and a broad range of other proposals that are part of his second-term agenda. The president has launched a new outreach to rank-and-file Republicans, and his Capitol Hill visit is one of several planned with lawmakers of both parties this week.
The fiscal blueprint released Tuesday by Budget Committee Chairman Paul Ryan, R-Wis., will be dead on arrival with the White House and Democrats controlling the Senate. But the point is to prove it's possible to balance the budget within 10 years by simply cutting spending and avoiding further tax hikes.
The latest Ryan plan generally resembles prior ones, relying on higher tax revenues enacted in January and improved Medicare cost estimates — along with somewhat sharper spending cuts — to promise balance.
Senate Democrats plan to offer a counterproposal Wednesday with higher spending on domestic programs and additional tax hikes on top of the higher rates imposed on top-bracket earners in January. That plan will, in turn, arrive as a dead letter in the GOP-controlled House.
Curiosity rover tests rock, shows ancient Mars had right ingredients to support microbes
LOS ANGELES — The Curiosity rover has answered a key question about Mars: The red planet in the past had some of the right ingredients needed to support primitive life.
The evidence comes from a chemical analysis by Curiosity, which last month flexed its robotic arm to drill into a fine-grained, veiny rock and then test the powder.
Curiosity is the first spacecraft sent to Mars that could collect a sample from deep inside a rock, and scientists said Tuesday that they hit pay dirt with that first rock.
"We have found a habitable environment that is so benign and supportive of life that probably if this water was around and you had been on the planet, you would have been able to drink it," said chief scientist John Grotzinger of the California Institute of Technology.
The rover made a dramatic "seven-minutes-of-terror" landing last August near the planet's equator. A key task: Find out if ancient Mars ever had conditions favorable for microscopic organisms.