Still, investigators do not think that Jennifer McVeigh played an active role in the bombing. But she does share many of her brother’s extremist political views. Law-enforcement officials say they have found multiple copies of antigovernment, white-supremacist literature in her home and truck, suggesting that she may have been involved in distributing such material. Jennifer also apparently burned a number of letters from her brother while she was staying in Pensacola, Fla., after the explosion. And the officials say she had burned other letters weeks before at her father’s home in Pendleton, N.Y. The FBI now has between 20 and 30 letters Tim McVeigh wrote to his sister. Many are innocuous, but others suggest that he was plotting something.

NEWSWEEK has obtained access to what law-enforcement officials believe to be the last letter Tim McVeigh sent to his sister before the bombing, dated March 25. “Still waiting on your letter as to whether you rcv’d my last letter. (About being ‘rock.’),” begins the unsigned letter. “That had a lot of sensitive material in it. So it’s important to know if you received it, or if it was intercepted (either by G-men or Dad). . . . Please respond ASAP, only on letter. If one is already en route, Don’t send another. Send no more after 01 APR, and the, even if it’s an emergency–watch what you say, because I may not get it in time, and the G-men might get it out of my box, incriminating you.”

Just what might incriminate Jennifer is anybody’s guess. But she may have known her brother was involved in some sort of covert activity well before the April 19 bombing. According to law-enforcement officials, she told friends at a party last December that “something big” was going to happen in April or May and that Tim was involved. She denies having said it. Investigators have also discovered that in 1992 Jennifer attempted to have a gun store in Lockport, N.Y., ship 700 rounds of 7.62-mm ammunition to an undisclosed location. When the store refused, she bought the shells and allegedly shipped them herself. Last week Jennifer hired legal counsel, and one of her attorneys said she could face federal charges, though he says she has consistently denied she had anything to do with the bombing.

A straight-A student at Niagara County Community College, Jennifer McVeigh until recently held a part-time job as a waitress at the Crazy Horse Saloon in nearby Tonawanda, N.Y. There she took part in a ritual known as Jell-O wrestling, in which waitresses grapple with male customers in a giant vat of lemon gelatin. What most interests the Feds now is whether Jenny the Jell-O Wrestler knew what her brother was doing with his spare time.