The one-minute, 35-second video opens with images that apparently show bystanders and Indian security forces beating a man on the ground with sticks.
The journalist from whom CBS News obtained the video says the man is Ajmal Qasab, who, according to a senior Indian police officer, .
The low-resolution video shows Qasab being beaten by men in white shirts after he allegedly tried to hijack a car. The photographer says he turned to face a group of bystanders and police holding an assault rifle and shot at them, prompting the violent reaction by the group.
Whistles are heard amid shouting as police signal for more help.
Qasab is beaten repeatedly on the ground before more police arrive and take him into custody.
Joint Police Commissioner Rakesh Maria said Qasab told police the group had intended to hit more targets during their attacks on India's financial capital.
"Lashkar-e-Taiba is behind the terrorist acts in the city," Maria told reporters. "The terrorists were from a hardcore group in the L-e-T."
"Ajmal Qasab has received training in an L-e-T training camp in Pakistan," he said. "Our interrogation indicates that the terrorists had other places that they also intended to target."
Police have said Qasab is 21-years-old and a Pakistani national.
Six Americans were among the 172 killed in last week's attacks. President Bush on Sunday in support of India following the siege.
Rice said Monday that the U.S. expects nothing short of complete cooperation in investigations into the terrorist rampage, and Pakistan's response will be a test of the will of the new civilian government.
"What we are emphasizing to the Pakistani government is the need to follow the evidence wherever it leads," Rice said. "I don't want to jump to any conclusions myself on this, but I do think that this is a time for complete, absolute, total transparency and cooperation and that's what we expect."
The Secretary of State spoke Monday during a visit to London, where she was to meet her British counterpart David Miliband before traveling to Brussels for a NATO gathering. On Wednesday, following the NATO meeting, she is scheduled to travel to New Delhi, according to her new itinerary.
"We share the grief and the anger of the Indian people but of course Americans were also killed in this attack and they were killed deliberately because they were Americans," Rice said during a press conference aboard her plane en route to London. "That makes this of special interest and concern to the United States."
Qasab is allegedly the same militant gunman pictured in one of the few still photos to surface of the attackers as they besieged 10 locations Wednesday night. An image captured by newspaper photographer Sebastian D'Souza shows a man in his early 20s, believed to be Qasab, walking calmly through Mumbai's train station with an assault rifle at his hip.
Many witnesses have said the gunmen were remarkably calm. D'Souza followed militants operating in the train station, taking photos throughout.
"This is where I got the picture of the two and they exchanged some couple of words and then the guy dropped his bag," said D'Souza, who works for the Mumbai Mirror. "I think it was empty there was no ammo in it - he dropped his bag and then moved forward and kept firing from the hips, never raised the gun, very cool."
Meanwhile, CBS News reporter Celia Hatton says authorities finished removing bodies from the Taj Mahal hotel on Monday, the final site of the Mumbai siege to be cleared, as schools and businesses reopened and commuters returned to work.
Security forces had been scouring the 565-room hotel, seen at left, for booby traps and bodies, and declared the landmark building cleared two days after they killed the last three militants holed up inside.
"We were apprehensive about more bodies being found. But this is not likely - all rooms in the Taj have been opened and checked," said Maharashtra state government spokesman Bhushan Gagrani.
The L-e-T has long been seen as a creation of the Pakistani intelligence service to help wage its clandestine war against India in disputed Kashmir.
In April 2006, the U.S. Department of State listed Jamaat-ud-Dawa as terrorist organizations for being an "alias" of Lashkar-e-Taiba.
The Pakistani government offered no immediate response.
Speaking earlier Sunday, a spokesman for a Jamat-ud Dawa denied any link to Lashkar-e-Taiba and said he condemned the attack.
"We condemn the killings of civilians. We condemn such killings in a terrorist activity, and at the same time we condemn it happening in the shape of state terrorism, as we see in Srinagar, Kashmir," Abdullah Muntazir said, referring to alleged Indian army atrocities in the disputed Kashmir region.
Despite India's claim, Pakistan's ambassador to the United States, Husain Haqqani, said, "I don't think that this is the time for India or anybody in India to accuse Pakistan. It's time to work with Pakistan. Pakistan is now a democracy. India is a democracy. And as two democracies, we need to strengthen each other, rather than fall into the trap of the terrorists, who want us to fight with each other so that they can get greater strength."
India repeatedly has accused Pakistan of complicity in terrorist attacks on its soil, many of which it traces to militant groups fighting Indian rule in the divided Himalayan territory of Kashmir. The U.S. has tried to persuade Pakistan to shift its security focus from India, with which it has fought three wars, to Islamic militants along the Afghan border.
As investigations continued into one of India's deadliest terrorist attacks, pressure mounted on the Indian government to account for what went wrong, reported Hatton. Two top security officials resigned over the weekend and India's Prime Minister has vowed to boost the size of the country's anti-terrorism forces, which face criticism for arriving at the scene long after the gunfire began.