Tell us, Tom Snyder, what's Charles Manson really like?

First of all, he's a tough interview. . .

That's the way it went at a combination press conference and screening of a special edition of "Tomorrow Coast to Coast" featuring cult leader, convicted mass murderer and special guest star Charles Manson. Tom Snyder and his executive producer Roger Ailes were in Screening Room 980 at NBC's New York headquarters to answer questions from a skeptical squad of television journalists stuffed with coffee and danish. Manson, who is not making many public appearances these days, remained in the Vacaville, Calif., correctional facility. The interview, tonight on Channel 4 at 12:30 a.m., is a unique opportunity to see the man who masterminded Sharon Tate's murder and mutilation -- and the death of eight others -- interacting, kind of, with Tom Snyder.

The question that came up, of course, was why would anyone want to give national television exposure, in a 53-minute interview yet, to "that son of a bitch," as one reporter daintily put it.

Mea culpas were not forthcoming from Tom Snyder.

"If you're looking for a confession, it's not here," Snyder said, even before the first volley of questions was served up by 30 reporters. "If you're looking for remorse, it's not here." Early in the session, Snyder noted that "there's not one person in this room who wouldn't have done it [the interview]," and not one person disagreed. Interviews with Charles Manson don't grow on trees, and Snyder seemed pleased that "I was there when the tree opened up."

The tree apparently only opened, though, with the help of a $10,000-consultation fee (Roger Ailes' figure) given to a "free-lance journalist" and former prison buddy of Manson's named Nuel Emmons. Ailes and Snyder agreed that Emmons' influence won them the session with Manson.Emmons is working on a book, "Manson by Manson" and according to Ailes, is seeking a publisher. Of course, they said, it is not the intent of "Tomorrow Coast to Coast" to help its "consultant" strike a book deal. Anyway, Snyder said, with so many books already out on the Manson affair, "who's going to buy this book?"

"Who's going to watch this show?" someone asked.

Lots of people. And they are in for some fascinating television. Tom Snyder seems to have approached this interview, conducted last Saturday in a 12-by-18-foot room in Vacaville, with a crusader's fervor. When the interview begins, Snyder's tie is already undone, and beads of perspiration are forming on his upper lip. Manson, looking like Gabby Hayes after a short hunger strike, is quibbling about the limited choice of chairs or stools. s(He stands for most of the interview.).

Manson vacillates between bravado, incoherency and comedy. When Snyder asks him if he was a heavy drug user, he replies: "No, I smoked a little grass, and I've taken some acid, mescaline, psilocybin, peyote and mushrooms, but actually take dope, no. I wouldn't take anything that I feel would hurt me."

Between Manson's outrageous drawling speeches and Snyder's emotion-ridden attempts to get him to 'fess up to the crimes, the interplay takes on the aspects of a challenging two-character Sam Shepard play. At one point, Snyder is almost pleading with "Charles" to tell him whether he tied up four people at the LaBianca home and told his minions to kill the prisoners. Manson is evasive, saying it's not so simple to answer the question. "Try it, try it, try it," Snyder almost begs him.

Manson still is evasive, but seems shaken. He plays with the microphone cord. Snyder prods him verbally, but no answer comes. A closeup shows the deep lines in Manson's bearded face, circling the remnants of a tattoo on the forehead. Snyder offers to let Manson hit him if only he'll answer the question. "Hit you?" asks Manson, who then goes off on some story about seeing a big, fat dead rat in the water. Just the kind of tangent that made the interview a hellish one for Snyder, who constantly urges Manson to "get off the space shuttle, Charles."

At times, Manson disembarks, and we get a deep, sobering look at someone possibly dangerously unhinged. Other times, Manson takes Snyder along on the space shuttle. By the end of the interview, which was cut nearly in half to avoid repetition, stony silences and flighty Manson raps apparently judged too bizarre for even late-night television, Snyder has dark circles under his eyes. He's played prosecutor, confessor, shrink and shrew with Manson, and drawn a bit of blood as well as some grotesquely funny responses.

"I don't think you can interview someone like that and be dispassionate," Snyder said at the press conference. "You can't go in there and play patty-cake." After the Q & A session, he elaborated further. When the Manson horrors were being revealed in court, Snyder lived across the canyon from the Melcher-Tate home, which he said he could see from his yard."I was a married person with a 6-year-old daughter," said Snyder. His fingers tightened around a perpetual cigarette with two inches of ash. Manson, he agreed with a wire service reporter, is indeed "a monster."

The "Tomorrow" interview shows something quite the contrary -- Manson as a human being who has lost his moorings, probably permanently. "Sometimes I'm scared to live," he tells Snyder. "Living is what scares me. Dying is easy. Getting up every day and doing this again and again is hard."