“We know you killed Cathy,” I continued. “The woman in my car, too. You were on the roof across from Casa Guatemala. I found your photo album. I saw what you did to those pictures of the women. And I saw needles in the medicine cabinet just like the one we found next to Cathy’s body.”

“You killed her because she didn’t love you anymore,” interrupted Lupe. “You felt she failed you.”

He looked down at her as though he had forgotten for a moment that he had her in his arms. He drew the knife up closer to her throat so that it was only an inch or two from her. “She never loved me.”

“She must have. If only for a little while. How’d you meet her?” Lupe chattered with the innocence of a schoolgirl. She looked absolutely sincere. And not afraid. Was it possible she felt sorry for him? Or was it one of her B-girl tricks?

Armando Diaz didn’t say anything.

“It was at Rudy’s studio when she went to get some photos done. You must have been there using the darkroom like the day I met you there.” I guessed.

His silence convinced me I was right.

The gun was heavy in my hand. When I’d bought it from Tim Watson, it had seemed so light. Did Armando Diaz see the erratic flutter of my hand? “What did you think when you saw her at the demonstrations in front of the Federal Building? You knew she wasn’t like you, she didn’t believe in the things you do.”

“Love is mightier than the sword,” misquoted Lupe.

“I thought I could change her,” he replied carelessly.

I was stunned. Didn’t he know about the heroin deal or the arms Cathy had wanted to buy?

“Poor Armando, poor Cathy. Love can be so unhappy,” Lupe murmured.

The knife wavered slightly in his hand.

Lupe used this opportunity to push at the arm holding the knife.

“You gave Cathy money,” I insisted.

“No! I don’t have to pay for sex,” he said, exploding at me. He stepped forward slightly. Now Lupe and Armando Diaz looked as if they were dancing. Lupe pushed him off balance so that he nearly stumbled and with a great effort she jerked free of him, falling almost to her knees. Breathlessly she ran the few yards between us.

“Yeah, you gave her money,” taunted Lupe, her hands on her hips and still breathing hard from the tussle with him.

“How much?” I added.

He looked down at the gun and smiled. He saw my hand trembling.

I tried to pull back the safety but couldn’t. My hand was shaking wildly and I couldn’t get my fingers to work.