As a first responder during the last year I have had the opportunity to baptise 2 recently deceased persons. One was a suicide and the other died during the commission of a robbery. If a Catholic lay person baptises someone in this situation is there a need or protocol to follow in informing the Church about it?
You should cease doing such baptisms until you receive instructions from your pastor on proper protocols for adults and children. Also, regarding timing of baptism, as it is not possible nor should you baptize the dead. The church has guidelines regarding this.
Can. 865 §1. For an adult to be baptized, the person must have manifested the intention to receive baptism, have been instructed sufficiently about the truths of the faith and Christian obligations, and have been tested in the Christian life through the catechumenate. The adult is also to be urged to have sorrow for personal sins.
§2. An adult in danger of death can be baptized if, having some knowledge of the principal truths of the faith, the person has manifested in any way at all the intention to receive baptism and promises to observe the commandments of the Christian religion.
Can. 868 §1. For an infant to be baptized licitly:
1/ the parents or at least one of them or the person who legitimately takes their place must consent;
2/ there must be a founded hope that the infant will be brought up in the Catholic religion; if such hope is altogether lacking, the baptism is to be delayed according to the prescripts of particular law after the parents have been advised about the reason.
§2. An infant of Catholic parents or even of non-Catholic parents is baptized licitly in danger of death even against the will of the parents.
878 If the baptism was not administered by the pastor or in his presence, the minister of baptism, whoever it is, must inform the pastor of the parish in which it was administered of the conferral of the baptism, so that he records the baptism according to the norm of ⇒ can. 877, §1.