The 180 military personnel sent included the Royal Tank Regiment, Royal Marines, and chemical-weapons specialists and bomb-disposal units.
A short distance away, a convoy of military vehicles rolled into the auto park at Salisbury District Hospital to recover a police auto.
Home Secretary Amber Rudd has visited the city centre and the hospital where Mr Skripal, 66, and Yulia, 33, remain after they were targeted in an "outrageous" chemical attack.
Counterterrorism police, who are leading the investigation, said in a March 9 statement, "The public should not be alarmed", adding, "military assistance will continue as necessary during this investigation".
Russian Federation has denied responsibility for the attack, which comes seven years after Mr Skripal was released from the country as part of a spy swap with the US.
"Once these are established, then and only then, will an appropriate and proportionate course of action be taken", the lawmaker said.
"We have to give the police all the space they need in order to collect all the information, to secure and to be able to be absolutely clear that there is no further risk", Rudd said.
In addition to his home and vehicle, police have cordoned off the cemetery where Skripal's wife is buried as well as The Mill pub in Salisbury.
Police said Det Sgt Bailey is conscious but "very anxious" about being exposed to a nerve agent.
Britain has said it will respond robustly if evidence shows Russian Federation was behind the attempted murder.
Britain's chief medical officer, Sally Davies, said on March 8 that the general public was not necessarily at high risk, but experts said nerve agents are unsafe and extremely volatile.
British authorities suspect the Russian government is behind the attack, the Washington Post reports.
Sergei Skripal and his daughter Yulia remain critically ill.
As the race to find out how the pair were poisoned - and who by - the Home Secretary has visited the scene where they were found. "People are right to want to know who to hold to account but if we are to be rigorous in this investigation we must avoid speculation and allow the police to carry on their investigation".
Alexander Litvinenko was an officer with the Russian Federal Security Service, but he fled to the United Kingdom where he was granted refuge.
Bob Seely, a Conservative lawmaker and member of Parliament's Foreign Affairs Committee, said that Britain should be cautious about laying blame but that circumstantial evidence raises suspicions of Russian involvement.
British media and politicians have said the attack on Sergei Skripal, who came to Britain in a spy swap in 2010, bears the hallmarks of a Russian operation.
A British inquiry concluded Putin probably approved the killing.
Officers were seen placing a blue forensic tent over his son's memorial stone before appearing to place items in several yellow barrels.
Moscow has reacted angrily to the accusations it was involved, with Foreign Minister Sergei Lavrov on Friday dismissing them as baseless "propaganda".