Peter Lovesey - Diamond Dust

That killer, according to the profilers who these days assist the police on all challenging murder inquiries, is most likely to be male, efficient, unexcitable, with a link to guns, and some knowledge of Bath. He drives a car. His friends or relatives probably have suspicions about him.

FRUSTRATION

Detective Superintendent Peter Diamond, the victim's husband, is 50, and has an outstanding record in bringing murderers to justice. He admits to frustration at having to stay at arm's length from the investigation. 'I know the reasons and I respect them. If I got involved I would be open to charges of bias. But it's hard. My heart wants to do what my head tells me I can't. I'd like to be working round the clock on this for Steph's sake. I'm an experienced investigator, and I have my own ideas on what should be done.' But he refuses to be critical of the detectives working on the case. 'This is about as tough as they come. You need luck on any case, and they haven't had much up to now.' Echoing McGarvie, he adds, 'My main worry is that soon the cost of all this will panic the people who hold the purse-strings into scaling everything down.'

When asked which of the main theories he subscribes to, Peter Diamond is cautious. 'They should rule nothing out until evidence justifies it. There are compelling reasons to suppose it was some kind of contract killing for revenge, but it's still possible that the killer was a loner acting for himself – or herself. It's not out of the question that a woman did this. And there may be a motive the murder squad are unaware of.'

The shooting of Stephanie Diamond on that February morning put tremendous strains on her husband. 'You find out how much you depended on someone when they are taken from you. She was a calmer personality than I could ever be, very positive, with a way of seeing to the heart of a problem. She understood me perfectly. I don't know of anything you could dislike in Steph, which makes her murder so hard to account for. The killer has to be someone who didn't know her at all, or some deluded crazy person.'

After the shooting there was the added ordeal of being questioned about his own movements. Peter Diamond shrugs and says, 'It had to be faced. I'd have pulled in the guy myself, whoever was the husband. You always take a long look at the husband in a case like this.' But if he was at work in Bath Police Station, surely he had a perfect alibi? 'Actually, no. On that morning I went straight to my office and worked alone. There was no one who could vouch for me.' He adds wryly, 'I may look big and threatening, but off duty I'm a baa-lamb. I think I convinced them in the end that I wouldn't have dreamed of harming my wife.'

Peter Diamond's fiftieth birthday came four weeks ago. 'I didn't do anything to mark it – but then I wouldn't have done much in normal circumstances. Oddly enough I discussed the birthday with Steph the night before she was killed, and persuaded her I didn't want a so-called surprise party with old cronies from years back. That's not my style. We would have gone out for a meal together, Steph and I, and had a glass or two.' He is in regular contact with Curtis McGarvie and has co-operated fully with the murder squad, even to having his home searched and his wife's private letters and diary taken away for examination. He is as puzzled as the murder squad over the diary entries mentioning somebody called T'. 'This must be the killer,' he says, 'and the odds are strong that the letter "T" was meant to mislead, but the diary mentions phone calls and an appointment in Royal Victoria Park, which Steph hardly ever visited, so it has to be the best clue we have. What foxes me completely is that she didn't say a word about going to the park that morning. My wife wasn't secretive. She was the most open of people. I find it hard to accept there was something hidden in her life, but what other explanation is there?'

Peter Diamond continues his work at Bath Police Station, busying himself on other cases, trying to block out the knowledge that the incident room for his wife's murder is just along the corridor. Shortly before the shooting he gave evidence in the murder trial of Jake Carpenter, a notorious Bristol gang leader who was given a life sentence for the sadistic killing of a young prostitute. The possibility of some kind of revenge killing by Carpenter's associates was a strong theory early in the case. It has still not been ruled out entirely, but intensive enquiries in Bristol have so far proved negative. Diamond himself agrees that it was probably a mistake to link the killing to the Carpenter conviction. 'My own reaction was the same as the squad's,' he says, 'but with hindsight we may have leapt to a premature conclusion and missed other leads. The first forty-eight hours in any inquiry are crucial.'

TENSION

They work in separate offices on the same floor of Bath Police Station in Manvers Street, these two experienced detectives. Curtis McGarvie is the outsider, the man drafted in from headquarters. He is at his desk by 8 a.m. There is an air of tension in the incident room and it isn't just the pressures of the case. For this should be Peter Diamond's domain. He has led the murder squad for eight years. McGarvie refuses to let sentiment trouble him. He is a gritty Glaswegian, thin as a thistle, with deep-set, watchful eyes, a professional to the tips of his toes, focused and unshakeable. 'If I were this killer on the run, I'd be sweating. I wouldn't want Curtis on my trail,' says a colleague at Avon & Somerset Headquarters who knows McGarvie well. He has a long string of successful prosecutions to his credit. But his team in Bath are Diamond's men and women, loyal to their chief, wanting passionately to achieve the breakthrough, yet unfamiliar with their temporary boss.

Meanwhile Peter Diamond sits alone in his office up the corridor sifting through other 'stickers', trying to give them his full concentration. He is a big, abrasive man who speaks his mind without fear or favour. Few in Bath's CID have escaped the rough edge of his tongue at some point in their careers. But right now there is a strong current of sympathy for this beleaguered man excluded from the action through no fault of his own. If commitment to the cause counts for anything, the killer of Stephanie Diamond will soon be found.

Reading the Chronicle piece, Diamond was surprised how much the journalist had coaxed from him. He couldn't fault the quotes. She'd done her job well. Deprived of Steph's company for all this time, he'd been a soft touch for a bright woman journalist. The interview, over coffee in Sally Lunn's, hadn't seemed at all intrusive. He'd found her interest agreeable, almost therapeutic, having his brain exercised with a series of unthreatening questions, the sort Steph put to him when he was more under pressure than usual. Thank God he hadn't said what he really thought of McGarvie.

For obvious reasons he'd kept quiet about the cringe-making incident of the revolver the search party had dug up, and he was glad McGarvie had not mentioned it either. His feelings about that gun were complex. There was a basinful of guilt. He deeply regretted being so stupid as to hang on to the damned thing all those years. It pained him that Steph had found it and been so troubled that she buried it. He was sick to the stomach that her last communication to him – a beyond-the-grave message – had to be a kind of rebuke, for all its sensitive phrasing. But he had to be grateful she'd written the note and buried it with the gun. One last rescue act. She had removed a great burden of suspicion from his shoulders. Imagine McGarvie's fury, just when he felt he'd got the sensational evidence he needed, at finding the note that put Peter Diamond in the clear. The counter-theory about Diamond finding the gun and murdering Steph with it and then reburying it had been the sophistry of a desperate, disappointed man.