The man who kidnapped Elizabeth Smart from her bedroom told the teen he was taking her for ransom, according to details revealed Friday night on "48 Hours Investigates."

Elizabeth Smart's mother, Lois Smart, told CBS reporter Jane Clayson that Mary Katherine heard Elizabeth ask her abductor, "Why are you doing this?"

"She thought he said he was after a ransom," Lois Smart said.

But following the hourlong television piece, Salt Lake City Police Chief Rick Dinse said it's hard to know if those were the abductor's words.

Dinse said the information about a ransom never surfaced in initial interviews with Mary Katherine following Elizabeth's June 5, 2002, abduction.

"We had interviewed her several times prior to that coming out," Dinse said. "She told that to her parents and that was ultimately told to us."

Dinse said a kidnapping for ransom is still one of three possible theories investigators are considering, along with a burglary gone bad and a sexually motivated crime.

"That's a possible piece of information," Dinse said. "We're looking at all of that, although it's sometimes hard to determine when somebody remembers something after periods of time. You can put some weight behind it but you can't be absolutely sure that that was accurate."

Still, Dinse said he thought the story was "well done" and hopes the piece will generate more tips to police. The police department beefed up its employees answering phones Friday night in anticipation of extra telephone calls. The television news piece aired just hours after Dinse, the FBI and Salt Lake City Mayor Rocky Anderson increased the reward for information that leads to the discovery of Elizabeth's body or identifies the kidnapper, whether dead or alive, from $25,000 to $45,000. The Smart family is still offering a $250,000 reward for Elizabeth's safe return.

The "48 Hours" piece revisited the numerous twists and turns in the Smart case and featured an interview with Mary Katherine and her four brothers, ages 4 through 16.

It was the first time since the kidnapping that Ed and Lois Smart allowed the media to interview their children. The "48 Hours" crew was not allowed to film the children's faces and was barred from asking Mary Katherine any questions about what she saw or heard when the intruder came into the room she shared with Elizabeth and led her away at gunpoint.

Mary Katherine did talk about her feelings and how she's dealt with her sister's abduction.

"It makes me sad to know that people in this country kidnap children and take them away from family and people who love them," Mary Katherine said.

Ed and Lois Smart praised Mary Katherine's courage in watching the kidnapper as she feigned sleep.

Lois Smart said Mary Katherine could hear the kidnapper talking to Elizabeth.

"She said Elizabeth had stubbed her toe on her chair in her bedroom and Elizabeth said, 'Ouch,' " Lois said.

Mary Katherine then heard the man tell Elizabeth, "You'd better be quiet and I won't hurt you," Lois said.

As part of her story, Clayson also retraced the investigation into former Smart handyman Richard Ricci. He remains at the top of investigators' list of potential suspects despite dying from a sudden brain hemorrhage Aug. 30, 2002.

In an interview with Clayson, Ricci's wife, Angela Ricci, reiterated her belief in her husband's innocence, stating that Ricci was in bed with her the night of the abduction.

The story also reviewed one of the puzzling pieces of evidence connected to Ricci — the extra 1,000 miles logged on his Jeep Cherokee after he returned the vehicle to mechanic Neth Moul for repairs June 8, 2002.

Moul told Clayson that before the kidnapping a woman calling herself Mrs. Ricci called his shop saying that Ricci needed the vehicle.

In her interview with "48 Hours," Angela Ricci denied calling the shop. Elizabeth Smart Task Force leader Capt. Cory Lyman also said investigators believe it was someone else who made that call.

Lyman also reiterated that the kidnapper cut the screen in the Smart family's kitchen window to make it look like the point of entry.

"The point of entry, I believe, was a ruse," Lyman said.

Instead, Lyman said, the kidnapper may have entered the Smart house through a door on the back porch using a key.