In Civil law, a conspiracy is the 'delict' or 'tort' of agreeing with others to cause damage to another by committing a lawful act by unlawful means or just by committing an unlawful act.
The courts try to exclude legitimate business agreements from the scope of conspiracy. In criminal law, conspiracy is a statutory offence committed by an agreement to a course of conduct, whether loosely or tightly decided, that, if carried out, will necessarily involve the commission of a criminal offence.

In some countries, as in federal United States, the agreement itself is a crime.

In the United States, the Constitution was ratified by 13 states and it is the heart of the US legal system. In 7 articles and 26 amendments, it lays down the political and legal structure of the federal government. Of these 26 amendments of the US Constitution, the first 10 amendments are known as the US Bill of Rights. Each state has its own constitutional documents. The federal government is delegated specific powers involving regulating interstate trade, taxation and war treaties. CONGRESS enacts laws. The executive function lies with the President of the United States. The US Constitution provides the checks and balances to allow the three divisions of government to cooperate.

So coming back specifically to 'conspiracy' in criminal law, this involves the element of MENS REA. In order to create a conspiracy words would have had to be spoken , even whispered , and other means of communications may possibly have been used.

Conspiracy to murder may involve the person who committed the act and a whole group of persons who hatched the idea to kill the person.

PUNISHMENT ON CONVICTION
As regards sentencing for conspiracy to murder Professor Dan Markel, and also murder conviction, it is well known through recent studies, that Florida is among the "SUNBELT STATES" which have experienced high levels of internal migration since the 1950s, based on climate; lifestyle and economic growth related to tourism, and real estate.

Florida has expanded its penal system. At the same time in Florida there is much litigation on prisoners' rights on the back of populist punitive politics and FSU is very involved.

Florida has strict 'due process' rules.

Florida was the state where the problem-solving court movement first began with the establishment of the Dade County Drug Court in 1989. Overcrowded jails, repeat offenders and a rising 'crack' epidemic is present. Also the first Mental Health Court was established in Florida in 1997.
In 1999, the state of Florida implemented several tough-on-crime types of measures and life sentences of 10 to 20 years.
By the year 2005 it was claimed that Florida's population increased by 2.5 million people or 16.8% and violent crime was reduced by 30%; gun crime was reduced by 28%. Yet executions (Death Sentences) remain high (Petersilia, J. and Reitz, K.R. (Eds) (2012) Oxford Handbook of Sentencing and Corrections, New York: Oxford University Press, pages 184-187).

In Florida, for capital verdicts, both jury and judge have responsibility for capital verdicts (Ibid, p 723).