Learn Spanish (Latin America): El atleta cometió un fraude grave; por lo tanto, recibe una suspensión. - The athlete committed a serious fraud; therefore, he receives a suspension.

Connectors of logical result like por lo tanto (therefore) declare what happens as a direct consequence of an established fact. Because the result is presented as real and factual—not doubtful or hypothetical—these connectors are followed by the indicative mood.

Could I use por eso instead of por lo tanto in this sentence?

Yes, but it changes the tone. Por eso (that's why) is very common in everyday speech. Por lo tanto (therefore) is more formal and analytical, which fits the official, rule-breaking context of this sentence.

Why is there a semicolon before por lo tanto and a comma after it?

When formal connectors like por lo tanto, en consecuencia, or por consiguiente link two independent clauses, standard Spanish punctuation uses a semicolon before the connector and a comma immediately after it.

The sentence switches from the past tense (cometió) to the present tense (recibe). Is that normal?

Yes, it perfectly matches the logic of the sentence! The athlete committed the fraud in the past (cometió), and as a logical consequence, they are currently receiving or currently hold the status of a suspension (recibe). Connectors like por lo tanto often bridge two different timeframes.