Answer based on context:

Coming off their hard-fought win over the Ravens, the Broncos traveled to Arrowhead Stadium for an AFC West duel with the Kansas City Chiefs on Thursday Night Football. There was no scoring in the first quarter, which included cornerback David Bruton forcing a fumble off Chiefs' running back Jamaal Charles at the Broncos' 6-yard line. The Chiefs grabbed the lead early in the second quarter, with Charles rushing for a 34-yard touchdown, then added to their lead, when cornerback Marcus Peters returned an interception off Broncos' quarterback Peyton Manning 55 yards for a touchdown. The Broncos responded with two touchdown passes by Manning &#8212; a 16-yarder to wide receiver Emmanuel Sanders followed by a 1-yard juggling touchdown catch by tight end Virgil Green just before halftime. The latter scoring play came after Chiefs' quarterback Alex Smith was intercepted by cornerback Aqib Talib deep in Chiefs' territory. That was Talib's 2nd pick in as many weeks. The two teams exchanged field goals in the third quarter &#8212; a 35-yarder by Chiefs' placekicker Cairo Santos and a 54-yarder by Broncos' placekicker Brandon McManus. Following an exchange of punts, the Chiefs were attempting to re-claim the lead midway through the fourth quarter, when Smith was intercepted by cornerback Chris Harris, Jr. at the Broncos' 10-yard line with 6:40 remaining. However, the Broncos went three-and-out, and were forced to punt. The Chiefs took a 24-17 lead six plays later, with running back Knile Davis rushing for an 8-yard touchdown with 2:27 left in the game. Manning then engineered a 10-play, 80-yard drive, culminating in a 19-yard touchdown pass to Sanders with 36 seconds left. The game appeared to be headed to overtime, however, on the initial play of the Chiefs' ensuing possession, Broncos' linebacker Brandon Marshall forced a fumble off Charles deep in Chiefs' territory, and cornerback Bradley Roby returned the fumble 21 yards for a touchdown with 27 seconds in the game. The Broncos' defense subdued the Chiefs' last drive.

Which player forced the first turnover of the game?
David Bruton