DENVER -- The trial of a man accused of killing Denver Broncos cornerback Darrent Williams enters its second week Monday with several crime-scene investigators taking the stand, and a former medical examiner who performed Williams’ autopsy is expected to testify.

Prosecutors said Willie Clark fired the fatal shots into a stretch limousine Williams was in, killing him almost instantly early New Year's Day 2007. The shooting followed an altercation involving other Denver Broncos in and outside the Safari club on Broadway.

Clark faces charges including first-degree murder and 16 counts of attempted murder.

4:15 p.m. Monday

Daniel "Ponytail" Harris testified he saw Willie D. Clark shoot at a limousine during a "blind-side hit" that killed Denver Broncos cornerback Darrent Williams early New Year's Day 2007.

Harris said Clark was driving a white Chevrolet Tahoe on Speer Boulevard as he strafed the side of a Hummer limousine carrying Williams and 14 others that night. Williams died within minutes and two other passengers were wounded, authorities said.

As Clark drove the SUV, Harris testified, “Willie's … leaning over the center console shooting out the window at the white limousine.”

"Any doubt in your mind that that was the man who was fired that weapon?" prosecutor Tim Twining asked, referring to Clark.

“No doubt in my mind," Harris replied. He added that he wasn't sure how many shots Clark fired with a "big, black semiautomatic handgun."

But Harris said he could see the bullets impacting the driver's side of the stretch-limo and shattering a window at the rear of the Hummer, where police say Williams was sitting when he suffered a fatal wound in his neck.

"It just seemed like it kept going on forever," Harris said. "It was like everything slowed down … like slow motion."

Clark "was just shooting and … his arm was jumping around. His hand was jumping around with the gun in his hand," Harris testified as Clark sat a few feet away in the courtroom. "It was just like: Boom! Boom! Boom! Boom! Boom!"

Courthouse security was extremely tight during the much-anticipated testimony of Harris, 39, a convicted drug dealer who appeared in court in a khaki inmate jail jumpsuit and shackles.

Harris said he has been placed in the federal witness protection program for the rest of his life, because of his decision to testify against Clark, whom he described as a member of a Denver street gang.

Harris is being guarded by U.S. marshals and several agents in suits with radio earpieces were guarding the courtroom and the hallway outside along with uniform deputies.

Clark awaits trial in an unrelated case for allegedly conspiring with two other men in the 2006 murder of Denver woman just days before she was to testify that a gang member had tried to kill her outside a nightclub.

Just minutes before the Williams shooting, Harris said he had gotten into the SUV outside the Safari nightclub on Broadway and he was sitting in rear right passenger seat next to the window, facing the limo as Clark slowed down along side it.

Mario Anderson was in the left rear passenger seat and "Markie" Jackson -Keeling was in the front right passenger seat, Harris testified. Anderson and Jackson-Keeling were jailed for contempt of court last week after they refused to testify in the murder case.

Harris, however, admitted that he was drunk that night and his eyes were blurry and burning after the nightclub's closing-time crowd had been maced outside by security guards. The security guards were breaking up a fight between Clark and fellow gang members and Denver Broncos players celebrating with Williams, authorities said.

"Explain to the jury, Mr. Harris, how it is that you had plenty to drink that night and you’d been maced to some extent (in the eyes), how it is that you can tell this jury under oath that it was this man (Clark), seated here was firing that gun into the limousine?" prosecutor Twining asked.

Harris replied that the sudden gunfire got his adrenalin pumping.

"Somebody (is) shooting a gun right there in your face … That’s going to sober you up," Harris said.

Harris insisted that he didn't notice anyone else firing from the SUV, even though police say at least two guns were fired from the Tahoe that night.

Defense attorneys have repeatedly suggested that Harris may have also fired a gun that night. Denver Bronco star Brandon Marshall and other witnesses identified Harris as a man who was acting "crazy" and fighting outside that club before the shooting.

"On your oath, Mr. Harris, on Jan. 1, 2007, did you have a gun?" Twining asked.

"No I didn't," Harris replied.

"On that night, that early morning hours, were you so enraged that you were driven to kill?" Twining asked.

"No, I didn’t," Harris insisted.

After the shooting, Harris said he saw the limo veer off into the grass beside Speer Boulevard.

He called the drive-by shooting a "blind-side hit, describing that as "when somebody is not prepared for it and you come up and hit them from the blind-side and drive off."

After the shooting, Harris said Clark began to speed off in the Tahoe.

"I told him (Clark). 'Don’t speed. Don't speed. Don't speed. Let me out,' " Harris recalled, adding that he feared the speeding SUV would attract police.

Clark slowed down and dropped Harris off, the witness said.

Days after the shooting, Harris said he confronted Clark and told him he should turn himself into police.

Harris said he told Clark he was "messing up everything in the neighborhood, making it hot for everybody" by bringing an intense police investigation to identified the killer of the popular Broncos player.

"(Clark) said he’s not doing 'all day.' All day meaning, he’s not doing life in prison," Harris testified.

Harris said Clark's refusal to come forward "made me feel scared."

The prosecutor asked why?

"Because, knowing … things that happen to witnesses, at any day I could be dead," Harris said.

The defense objection was sustained by Judge Christina Habas. She told the jury to "completely disregard Mr. Harris' last answer. It was complete speculation."

Yet, Harris was allowed to say he so feared for his safety that a week after the killing he fled to Mexico for six months.

Harris said he waited for his family to safely get out of Colorado, then he returned to the Denver in June 2007. He was arrested at Denver International Airport in connection with a federal drug-trafficking indictment.

While defense attorneys contend Harris will get a reduced sentence in exchange for his testimony against Clark, Harris said he had already reached a plea agreement with federal prosecutors before he ever gave a statement to Denver police in the Williams slaying.

Harris was facing up to life in federal imprisonment for drug trafficking. He acknowledged that federal prosecutors cut him a deal allowing him to plead guilty to a single count of crack cocaine trafficking and dropped all other charges.

While federal prosecutors have recommended he served five years in prison, Harris said a federal judge will ultimately decide his sentence.

In exchange for his drug dealing plea agreement, Harris said, he must "cooperate and be as truthful as possible” with any state or federal investigation.

Harris said he was also granted immunity from prosecution in the Williams' killing in exchange for his testimony.

But, Harris said, "If I lie ...I would can get prosecuted to the fullest extent of the law ... in all jurisdictions."

“If some credible evidence comes forward showing that you were involved, you were shooting into that limousine on Jan. 1, 2007, what happens to your federal agreement, Mr. Harris?" Twining asked.

"It’s null and void,": said Harris, adding: “I get prosecuted." He would also lose his witness protection agreement.

Defense attorney Darren Cantor began his cross-examination by calling Harris a liar who has "a habit of telling stories to get yourself out of trouble."

"No I don't," Harris replied.

But Cantor went on to show how Harris has lied to police about his identity during a 2002 Denver traffic stop and a 1991 arrest for receiving stolen goods in Riverside, Calif.

3 p.m. Monday

Broncos cornerback Darrent Williams was killed by a single bullet wound that pierce vital veins and an artery in his neck, causing him to bleed to death in about minute, former Denver Chief Medical Examiner Robert Whitmore testified Monday.

“In deference to the Williams family,” trial Judge Christina Habas said the graphic autopsy photographs of the slain 23-year-old cornerback would only be shown to the jury and not aired on monitors facing the public galleries in the court and the City Council chambers.

Williams was killed by “a single gunshot wound of his neck,” Whitmore said under questioning by prosecutor Bruce Levin.

The bullet entered the left side of his neck, tore through the left jugular vein, cut through his airway, pierced the right jugular vein and the carotid artery before exiting the right side of his neck, Whitmore said.

Because the torn artery is under high pressure, Williams died from “massive bleeding” in “at most a matter of a few minutes, maybe even just a minute,” the doctor said.

The bullet entry wound had several small cuts and was larger than normal hole, Whitmore said.

This indicated that the bullet had struck the side of the limousine that Williams was riding in and sent window glass or metal fragments into his neck, Whitmore said.

The death was ruled a homicide, with cause of death being the "perforating gunshot wound of the neck," Whitmore said.

12:15 p.m. Monday

Denver police homicide Lt. Jon Priest testified Monday about the discovery of a spray-painted and burned Chevrolet Tahoe that was found ditched in northeast Denver days after the New Year’s Day 2007 slaying of Broncos cornerback Darrent Williams.

Prosecutors accuse Clark of firing the fatal shots from the white Tahoe at a limousine carrying Williams and his friends from a nightclub. Clark and other men, whom prosecutors referred to as fellow gang members, are accused of clashing with Williams and Broncos teammates Brandon Marshall and Elvis Dumervil at the Safari club on Broadway before the killing.

Priest confirmed the torched Tahoe was found about six blocks from a field where a gun barrel from the murder weapon was recovered.

The jury was shown photographs displaying how someone had spray-painted the sides and hood of the Tahoe black, but left the top of the SUV its original white color.

Priest said the interior of the SUV reeked of fuel and smoke during an apparent attempt to burn the Tahoe. Photos showed how the interior door panels and carpet were burned.

The implication is that someone might have painted and torched the suspect vehicle to prevent police from locating it and to destroy evidence, including fingerprints and DNA.

The SUV belonged to Brian Hooks, who police said is a fellow gang member of Clark. Both men are charged along with a third defendant in the unrelated 2006 slaying of a woman, Kalonniann Clark, days before she was to testify against Hicks for attempting to kill her outside a night club a year earlier.

11 a.m. Monday

A firearms expert testified Monday that the fatal bullet recovered from the neck of slain Denver Bronco Darrent Williams was fired from a Beretta handgun barrel found discarded the day after the early New Year’s Day killing.

Police testified Friday that the barrel was found in an Aurora field by an electrical lineman near where authorities recovered the torched Chevrolet Tahoe from which prosecutors accuse Clark of firing the fatal shots.

Retired Denver crime-scene Detective Edward Frushour testified that he confirmed that recovered barrel fit a Beretta .40-caliber semiautomatic handgun.

Frushour, a firearms expert, was able to test-fire bullets using the recovered barrel fitted into a Beretta handgun frame for comparison to slugs recovered from the shooting.

Frushour said his analysis showed a bullet slug “recovered from the neck of the decedent” was fired from the barrel found in the field. Several other bullet slugs recovered from inside and outside the white Hummer stretch-limo were also fired from the Beretta, he added.

Police said at least 15 shots were fired during the alleged drive-by strafing of the limousine. Frushour said he believes two guns, including a .45-caliber semiautomatic handgun that might have been a Glock model, were used in the shooting.

Yet, defense attorney Abraham Hutt asked if it’s possible that up to four handguns were used in the attack.

“Yes,” Frushour replied.

The defense is trying to raise doubts about whether prosecutors can prove that Clark -- not someone else in the SUV -- fired the fatal shot.