Defense attorneys for Oklahoma City bombing conspirator Terry Nichols shifted the focus of his murder trial to John Doe No. 2 as they began presenting their case.

Defense attorneys questioned six witnesses Thursday on an issue that is key to Nichols' defense, that Timothy McVeigh had contact with people other than Nichols in the final days before the bombing of the Oklahoma City federal building (search).

Sketches bearing the image of John Doe No. 2 (search), a muscular, dark-skinned suspect who does not resemble Nichols, were flashed across television monitors during testimony.

The defense alleges McVeigh received substantial help from others in planning the April 19, 1995, bombing of the Alfred P. Murrah Federal Building (search) and that Nichols was set up to take the blame. The blast killed 168 people and injured more than 500 others.

Lea McGown, owner of the Dreamland Motel in Junction City, Kan., testified that she rented a room to McVeigh from April 14 to April 18.

McGown also said she heard McVeigh talking with one or two other men in his room one night. She said she couldn't identify them but thought one of the men had telephoned McVeigh's room earlier.

"I heard Mr. McVeigh's voice and another velvety voice and a third voice in the background," McGown said. On cross examination, she said the third voice could have come from a television set.

The day McVeigh checked in, a man came in the motel lobby and asked directions to Room 25, where McVeigh was staying, McGown said. She gave the man directions to the barber shop where McVeigh was getting his hair cut, she said.

McGown said she didn't remember the man's face but that he was between 25 and 35 years old, had light skin and eyes and a small build.

She said she remembered seeing McVeigh with a large Ryder rental truck on the Sunday before the bombing, one day before prosecutors allege he leased it at Elliott's Body Shop using the alias Robert Kling.

McGown also said she never saw McVeigh with anyone else and couldn't identify an FBI sketch of John Doe No. 2. However, she did identify two phone calls that were made from the room to Nichols' home in Herington, Kan.

The defense's first witness was FBI artist Raymond Rozycki, who drew the sketch based on a description by Elliott's Body Shop employee Tom Kessinger.

The drawing depicted a heavy, well-built man with brown eyes and hair who witnesses said was with McVeigh at the leasing agency. Rozycki also drew a sketch of McVeigh.

Kessinger said the man wore a black T-shirt, a baseball cap with white and blue zigzag patterns and had a tattoo on his left arm.

Hilda Lopez, a former housekeeper at the Dreamland Motel, said she saw a man wearing a cap with a similar pattern walk toward a Ryder truck that was parked in the motel parking lot on April 17.

The man was well-built, had short black hair and a dark complexion that made him appear Hispanic, she recalled.

A former Chinese food deliveryman, John Jeffrey Davis, said he brought an order to a man who was neither McVeigh nor Nichols at McVeigh's motel room on April 15.

Davis identified a composite sketch of the man drawn by an artist in April 1996, but it didn't match FBI sketches of McVeigh or John Doe No. 2.

Also Thursday, Judge Steven Taylor replaced a juror who suffered a heart attack before arriving in court. The excused juror, Robert Dale McCoy, is expected to make a full recovery, Taylor said. He was replaced by a female alternate, changing the makeup of Nichols' jury to six men and six women.

Nichols, 49, is serving a life prison sentence on involuntary manslaughter and conspiracy counts in the deaths of eight federal agents in the bombing.

In Oklahoma, he faces 161 counts of first-degree murder for the deaths of the other 160 victims and one victim's fetus.

McVeigh was convicted on federal murder charges and executed in 2001.