Was born in the year 1887 in Yabucoa, Puerto Rico to Juan Lastra and Alfonsina Charriez.
Alfonso Lastra Chárriez was a member of the Liberal Party of Puerto Rico.
Got elected to the Puerto Rico House of Representatives that included a term as Speaker pro tempore of the House of Representatives of Puerto Rico from 1921 to 1924.
In 1937 was elected as an at-large member for the Puerto Rico Senate.
Was a prominent member of the Liberal Party of Puerto Rico.