Anagrammatically speaking 2

Question

Fill in the blanks below. Each sentence uses words that are anagrams of each other. In each pair of sentences, solve the first sentence, change one letter of an answer-word from that sentence, and shuffle it to form the answer-words for the second sentence. The answer-words in all sentences are the same length. Other than that, there is no correlation between answer-words from one sentence-pair to the next. All resulting sentences must make sense, and must use answer-words that are legal in Scrabble.

A similar earlier puzzle is here:
Anagrammatically speaking

Pair 1:

Police have determined that the ______ came into the country through ______ routes.
The professor explained that the ______ tip allows the rocket to be more aerodynamic in the atmospheric phase of flight, which the ______ student wrote down as “pointy = faster”.

Pair 2:

When the royals went crab-hunting for the first time, the ______ learned the hard way about ______.
The ______ left the faucet running, and two days later the ______ ran out of water.

Pair 3:

Dolly Lloyd runs hunting cabin ______, and each one has ______ over the fireplace.
The ______ left office after he was accused of ______.

Answer 1

An answer for pair 1:

Police have determined that the cocaine came into the country through oceanic routes.

Change the E to L

The professor explained that the conical tip allows the rocket to be more aerodynamic in the atmospheric phase of flight, which the laconic student wrote down as “pointy = faster”.

An answer for pair 2:

When the royals went crab-hunting for the first time, the princes learned the hard way about pincers.

Change the P to T

The cretins left the faucet running, and two days later the cistern ran out of water.

An answer for pair 3:

Dolly Lloyd runs hunting cabin rentals, and each one has antlers over the fireplace.

Change the L to O

The senator left office after he was accused of treason.