The Lead Masks Case

Summary

Two electronics technicians were found dead on a hillside above Niterói, lying side by side in formal suits and waterproof coats, each wearing a mask of lead over his eyes.

Beside them were an empty water bottle, a packet containing two wet towels, and a notebook. The notebook contained a schedule. It told them what time to be in position, what time to swallow capsules, and to wait for a signal.

There is a straightforward explanation for what killed them. It cannot be tested, because the one examination that could have settled it was either never carried out or was made on bodies too decomposed to give an answer.

What is documented

The men. Manoel Pereira da Cruz and Miguel José Viana, electronics technicians from Campos dos Goytacazes, in the north of Rio de Janeiro state. They left home on 17 August 1966, telling their families they had business to attend to and needed to buy materials. They were carrying a substantial sum of money.

The discovery. On 20 August, Jorge da Costa Alves, an 18-year-old flying a kite on Vintém Hill above Niterói, found their bodies.

The scene. They lay side by side. Both were dressed formally, in suits, and both wore waterproof coats. Both had a mask of lead over the eyes, of the kind used as shielding against radiation. The men were electronics technicians and could have made them.

Beside the bodies were an empty water bottle, a packet containing two wet towels, and a notebook.

The notebook. It contained a schedule. In substance, and translations differ in their details: be at the agreed place at 16:30, swallow capsules at 18:30, and after the effect begins, protect the metals and wait for the signal, with the mask.

The absence of violence. No wounds. No sign of a struggle. No sign of robbery at the scene, although most of the money was never found: only a small part of it was on the bodies.

The last sighting. A waitress at a bar in Niterói sold them a bottle of water. She said Miguel seemed very nervous and kept checking his watch.

The autopsy, which is the whole of the problem. The bodies were found roughly three days after death, in the open, in a Brazilian August. They were badly decomposed.

Most accounts of the post-mortem report that no toxicological examination was carried out. Others state that toxicological tests were run in 1966, and again after an exhumation in August 1967, and were negative, on material that was decomposed or saturated with embalming formaldehyde. Sources differ on why: some hold that the state of the bodies made it impossible; some hold that the viscera were never analysed, or were lost. The registry notes the discrepancy and does not resolve it.

What is not in dispute is the consequence. No usable toxicology exists, in a case in which two men left a written note to themselves saying they intended to swallow capsules.

The context. The men were involved in spiritualist practice, and belonged to a circle that experimented with séances and with attempts at contact.

Leading explanations

They poisoned themselves in the course of a ritual. Leading, and untestable.

The reconstruction is not exotic. Two men, engaged in an occult practice, travelled to a hill at an appointed hour, made shielding masks, wrote themselves a schedule, took capsules of something at the time the schedule specified, put the masks on, and waited for a signal that did not come.

The substance was intended to produce an effect. It killed them.

This accounts for the notebook, the timing, the masks, the towels, the absence of injury, the formal clothes, and the fact that they went there voluntarily and prepared. It accounts for everything.

It cannot be confirmed. The evidence that would have confirmed it was in their bodies, and it was never examined in a state that could show it.

Murder. Advanced at the time. It has to explain why two men wrote themselves a schedule for swallowing capsules and then went to a hilltop wearing masks they had made, which is a great deal for a murder theory to carry.

Extraterrestrial contact. The case is a fixture of the UFO literature, on the strength of the masks and the reference to a signal. It is worth noting what the theory actually requires: that the men's own written expectation of making contact is treated as evidence that contact occurred. That is not how evidence works, and the men's expectation is the one thing in the case that is fully documented.

Current status

Unsolved, and the registry wants to be precise about what that means here.

It is not unsolved because the evidence is baffling. It is unsolved because the evidence was not collected. Two men died with a written statement of intent in their pockets, and what was in them was never analysed in a state that could show it.

The mystery of the Lead Masks case is not a mystery about two men on a hill in 1966. It is a mystery preserved by an autopsy, and it is now permanent, because the bodies are sixty years gone and nothing can be recovered from them.

Last reviewed: September 2026. Records are provisional. Where the evidence changes, the entry changes. Found an error? Tell us.